Method and device for transmitting acknowledgement or negative acknowledgement indication information

ABSTRACT

The present invention discloses a method and device for transmitting ACK/NACK indication information. A network-side device configures at least two carriers for a UE; transmits PDCCH information to the UE; selects one of at least two timing relationships as a first timing relationship; determines a corresponding third uplink subframe and first carrier; indicate related information corresponding to the third uplink subframe and the first carrier to the UE; in the third uplink subframe of the first carrier, determines a first channel resource, and indicates the first channel resource to the UE; and receives an ACK/NACK fed back by the UE on the allocated resource.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2012/074523, filed on Apr. 23, 2012, which claims priority toChinese Patent Application No. 201110100737.7, filed on Apr. 21, 2011,both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the communications field, and inparticular, to a method and device for transmitting acknowledgement ornegative acknowledgement indication information.

BACKGROUND

In an LTE (Long Term Evolution, long term evolution) TDD (Time DivisionDuplex, time division duplex) or FDD (Frequency Division Duplex,frequency division duplex) system, or a system where TDD and FDDcarriers are aggregated, a base station may configure at least twocarriers for a UE (User Equipment, user equipment), and transmit data tothe UE through at least two carriers, where the configuration isreferred to as carrier aggregation. The base station transmits PDCCH(Physical Downlink Control Channel, physical downlink control channel)information to the UE in a downlink subframe, where the PDCCHinformation indicates scheduling information of a PDSCH (PhysicalDownlink Shared Channel, physical downlink shared channel) carried inthe downlink subframe. The UE determines an uplink subframe according toa timing relationship between the subframe carrying the PDSCH and asubframe carrying an ACK (acknowledgement) or NACK (negativeacknowledgement) corresponding to the PDSCH, and feeds back the ACK/NACKcorresponding to the PDSCH in the uplink subframe of a primary carrier.

For carrier aggregation, after the base station transmits downlink datato the UE, the UE needs to feed back a corresponding ACK/NACK to thebase station, where, if the UE feeds back an ACK, it indicates that datatransmission is correct, or if the UE feeds back a NACK, the basestation initiates corresponding retransmission.

However, the conventional ACK/NACK transmission method is applicable toonly carrier aggregation of at least two TDD carriers with the sameuplink and downlink subframe configurations, or carrier aggregation ofat least two FDD carriers. When at least two TDD carriers of differentuplink and downlink subframe configurations are aggregated, or at leastone FDD carrier and at least one TDD carrier are aggregated, especiallywhen a TDD carrier is used as a primary carrier, it is possible that anACK/NACK cannot be fed back on the primary carrier, and no solution forfeeding back the ACK/NACK is available at present.

SUMMARY

In order that an ACK/NACK may be fed back when carriers of differentuplink and downlink subframe configurations are aggregated, the presentinvention provides a method and a device for transmittingacknowledgement or negative acknowledgement indication information.

The technical solution are as follows:

A method for transmitting acknowledgement or negative acknowledgementindication information includes:

configuring, by a network-side device, at least two carriers for a userequipment UE, where the carriers include one primary carrier and atleast one secondary carrier;

transmitting, by the network-side device, PDCCH information to the UE ina first downlink subframe, where the PDCCH information indicatesscheduling information of a PDSCH carried in a second downlink subframe;

selecting, by the network-side device, one of at least two timingrelationships between the subframe carrying the PDSCH and a subframecarrying an ACK/NACK corresponding to the PDSCH, as a first timingrelationship, where the first timing relationship meets a firstcondition, and the first condition is that on a first carriercorresponding to the first timing relationship, a subframe of the sametime as the second downlink subframe is a downlink subframe; determininga third uplink subframe corresponding to the first timing relationshipand used for the UE to transmit the ACK/NACK corresponding to the PDSCH;and determining the first carrier used for the UE to transmit theACK/NACK corresponding to the PDSCH;

indicating, by the network-side device, related informationcorresponding to the determined third uplink subframe and the firstcarrier to the UE;

in the third uplink subframe of the first carrier, determining, by thenetwork-side device, a first channel resource used for the UE to feedback the ACK/NACK corresponding to the PDSCH, and indicating the firstchannel resource to the UE; and

receiving, by the network-side device, the ACK/NACK fed back by the UEon the first channel resource in the third subframe of the firstcarrier.

Another method for transmitting acknowledgement or negativeacknowledgement indication information includes:

determining, by a UE, two carriers configured by a network-side devicefor the UE, where the carriers include one primary carrier and at leastone secondary carrier;

receiving, by the UE, PDCCH information transmitted by the network-sidedevice in a first downlink subframe, where the PDCCH informationindicates scheduling information of a PDSCH carried in a second downlinksubframe;

obtaining, by the UE, indication information transmitted by thenetwork-side device, and determining, according to the indicationinformation, a third uplink subframe and a first carrier that aredetermined by the network-side device for the UE and used for ACK/NACKfeedback, where a first timing relationship corresponding to theindication information meets a first condition: on a first carriercorresponding to the first timing relationship, a subframe of the sametime as the second downlink subframe is a downlink subframe;

obtaining, by the UE, a first channel resource allocated by thenetwork-side device for the UE and used for feeding back an ACK/NACKcorresponding to the PDSCH; and

transmitting, by the UE, the ACK/NACK corresponding to the PDSCH on thefirst channel resource in the third uplink subframe of the firstcarrier.

The present invention also provides a network-side device, where thenetwork-side device includes a transmitting unit, a receiving unit, anda processing unit, where:

the transmitting unit is configured to notify a UE of carriersconfigured by the processing unit; transmit PDCCH information to the UEin a first subframe, where the PDCCH information is used to indicatescheduling information of a PDSCH carried in a second downlink subframe;and indicate, to the UE, related information corresponding to a thirduplink subframe and a first carrier that are determined by theprocessing unit and a first channel resource determined by theprocessing unit;

the processing unit is configured to configure at least two carriers forthe UE, where the carriers include one primary carrier and at least onesecondary carrier; select one of at least two timing relationshipsbetween the subframe carrying the PDSCH and a subframe carrying anACK/NACK corresponding to the PDSCH, as a first timing relationship,where the first timing relationship meets a first condition, and thefirst condition is that on a first carrier corresponding to the firsttiming relationship, a subframe of the same time as the second downlinksubframe is a downlink subframe; determine a third uplink subframecorresponding to the first timing relationship and used for the UE totransmit the ACK/NACK corresponding to the PDSCH; determine the firstcarrier used for the UE to transmit the ACK/NACK corresponding to thePDSCH; and in the determined third uplink subframe of the first carrier,determine a first channel resource used for the UE to feed back theACK/NACK corresponding to the PDSCH; and

the receiving unit is configured to receive the ACK/NACK fed back by theUE on the first channel resource in the third subframe of the firstcarrier.

The present invention also provides a user equipment, including: areceiving unit, a processing unit, and a transmitting unit, where:

the receiving unit is configured to receive information about twocarriers allocated by a network-side device for the user equipment UE,where the carriers include one primary carrier and at least onesecondary carrier; receive PDCCH information transmitted by thenetwork-side device to the UE in a first downlink subframe, where thePDCCH information indicates scheduling information of a PDSCH carried ina second downlink subframe; receive indication information transmittedby the network-side device, where a first timing relationshipcorresponding to the indication information meets a first condition: ona first carrier corresponding to the timing relationship, a subframe ofthe same time as the second downlink subframe is a downlink subframe;and receive information about a first channel resource allocated by thenetwork-side device for the UE and used for feeding back an ACK/NACKcorresponding to the PDSCH;

the processing unit is configured to determine, according to theindication information received by the receiving unit, a third uplinksubframe and a first carrier that are determined by the network-sidedevice for the UE and used for ACK/NACK feedback; and determine,according to the information about the first channel resource receivedby the receiving unit, to transmit the ACK/NACK corresponding to thePDSCH on the first channel resource in the third uplink subframe of thefirst carrier; and

the transmitting unit is configured to transmit the ACK/NACKcorresponding to the PDSCH on the first channel resource in the thirduplink subframe of the first carrier.

The technical solutions provided by the present invention bring thefollowing benefits:

By using the above implementation solutions, in a system where at leasttwo TDD carriers of different uplink and downlink subframeconfigurations are aggregated or a system where at least one FDD carrierand at least one TDD carrier are aggregated, a network-side deviceselects a first timing relationship from at least two timingrelationships, and on a first carrier corresponding to the first timingrelationship, a subframe of the same time as the second downlinksubframe is a downlink subframe, thereby configuring a subframe, acarrier, and a corresponding channel resource that may be used forACK/NACK feedback for the UE. Therefore, it can be guaranteed that theUE not only can perform ACKK/NACK feedback, but also can performflexible ACK/NACK feedback. In addition, the solutions of the presentinvention are also applicable to a system where at least two TDDcarriers of the same uplink and downlink subframe configurations areaggregated, or a system where at least two FDD carriers are aggregated,or similar systems.

In addition, the above implementation solutions make it possible tochoose to feed back the ACK/NACK in different carriers or differentsubframes of a same carrier. Therefore, the solutions may also balanceACK/NACK feedback loads on all carriers or all subframes.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the technical solutions in the embodiments of the presentinvention more clearly, the following briefly introduces theaccompanying drawings needed for describing the embodiments. Apparently,the accompanying drawings in the following description show merely someembodiments of the present invention, and a person of ordinary skill inthe art may still derive other drawings from these accompanying drawingswithout creative efforts.

FIG. 1 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 1 of the present invention;

FIG. 2 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of uplink and downlink subframeconfigurations and timing relationships in carrier aggregation accordingto Embodiment 1 of the present invention;

FIG. 4 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 2 of the present invention;

FIG. 5 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 2 of the present invention;

FIG. 6 is a schematic diagram of uplink and downlink subframeconfigurations and timing relationships in carrier aggregation accordingto Embodiment 2 of the present invention;

FIG. 7 is a schematic diagram of binding acknowledgement or negativeacknowledgement time domain portions in aggregation of TDD carriers ofdifferent uplink and downlink configurations according to Embodiment 3of the present invention;

FIG. 8 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 3 of the present invention;

FIG. 9 is a flowchart of a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD systemaccording to Embodiment 3 of the present invention;

FIG. 10 is a schematic structural diagram of a network-side deviceaccording to Embodiment 4 of the present invention;

FIG. 11 is a schematic structural diagram of a user equipment accordingto Embodiment 5 of the present invention;

FIG. 12 is a schematic structural diagram of a network-side deviceaccording to Embodiment 6 of the present invention;

FIG. 13 is a schematic structural diagram of a user equipment accordingto Embodiment 7 of the present invention;

FIG. 14 is a schematic structural diagram of a network-side deviceaccording to Embodiment 8 of the present invention;

FIG. 15 is a schematic structural diagram of a user equipment accordingto Embodiment 9 of the present invention;

FIG. 16 is a flowchart of another method for transmittingacknowledgement or negative acknowledgement indication informationaccording to Embodiment 2 of the present invention;

FIG. 17 is a flowchart of another method for transmittingacknowledgement or negative acknowledgement indication informationaccording to Embodiment 2 of the present invention;

FIG. 18 is a schematic structural diagram of another network-side deviceaccording to Embodiment 6 of the present invention; and

FIG. 19 is a schematic structural diagram of another user equipmentaccording to Embodiment 7 of the present invention.

DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages of thepresent invention more comprehensible, the following further describesthe embodiments of the present invention in detail with reference to theaccompanying drawings.

Embodiment 1

This embodiment provides a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD system. Asshown in FIG. 1, this method may be executed by a network-side device,and specifically includes:

S11. A network-side device configures at least two carriers for a UE,where the carriers include one primary carrier and at least onesecondary carrier.

S12. The network-side device transmits PDCCH information to the UE in adownlink subframe, where the PDCCH information indicates schedulinginformation of a PDSCH carried in a downlink subframe; the PDCCHinformation indicates an ACK/NACK channel resource corresponding to thePDSCH, where the ACK/NACK channel resource is carried in a first uplinksubframe of a secondary carrier, where the first uplink subframe isdetermined according to a timing relationship between the PDSCH and theACK/NACK corresponding to the PDSCH, and a subframe of the same time asthe first uplink subframe is a downlink subframe on a primary carrier.

The ACK/NACK resource is an ACK/NACK resource of a PUCCH format (format)3, or the ACK/NACK resource is a group of ACK/NACK resources of a PUCCHformat 1b. The number of resources in a group of ACK/NACK resources ofthe PUCCH format 1b may be 2, 3, or 4.

In addition, the network-side device may be specifically a base station,which is the same for the subsequent embodiments.

S13. The network-side device receives, in a first uplink subframe of thesecondary carrier carrying the ACK/NACK channel resource, the ACK/NACKfed back by the UE.

The method for transmitting acknowledgement or negative acknowledgementindication information in a TDD system according to this embodiment maybe as shown in FIG. 2; the method may also be executed by a UE, andspecifically includes:

S21. A UE receives PDCCH information transmitted by a network-sidedevice to the UE in a downlink subframe.

S22. The UE determines, according to scheduling information carried inthe PDCCH information, a PDSCH scheduled by the PDCCH information;determines, according to the indication of the PDCCH information, anACK/NACK channel resource corresponding to the PDSCH; determines,according to a timing relationship between the PDSCH and the ACK/NACKcorresponding to the PDSCH, a first uplink subframe used for feedingback the ACK/NACK, where a subframe of the same time as the first uplinksubframe is a downlink subframe on a primary carrier; and determines asecondary carrier carrying the ACK/NACK channel resource.

S23. The UE feeds back, on the determined ACK/NACK channel resource, theACK/NACK corresponding to the PDSCH, where the ACK/NACK channel resourceis located in a first uplink subframe of the determined secondarycarrier.

In the embodiment of the present invention, a primary carrier may alsobe called a primary cell (Primary cell, Pcell), and a secondary carriermay also be called a secondary cell (Secondary cell, Scell).

Using FIG. 3 as an example to describe the above method, it is assumedthat a CC (Component Carrier, component carrier) of configuration 1 is aprimary carrier and that a CC of configuration 2 is a secondary carrier.According to the rule in the prior art that the ACK/NACK can be fed backonly on the primary carrier, because subframe 7 of the secondary carrieris an uplink subframe, and subframe 7 of the primary carrier is adownlink subframe, four ACKs/NACKs in subframe 7 cannot be fed back onthe primary carrier. According to the method of this embodiment, fourACKs/NACKs in subframe 7 may be fed back on the secondary carrier. TheACKs/NACKs in subframe 3 and subframe 4 are fed back on the primarycarrier. The ACKs/NACKs in subframe 2 may be fed back not only on theprimary carrier but also on the secondary carrier.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier; if there is one secondarycarrier, the ACK/NACK channel resource is carried in a first uplinksubframe of the first secondary carrier; and/or, if there are two ormore first secondary carriers, the ACK/NACK channel resource is carriedin a first uplink subframe of one secondary carrier among the firstsecondary carriers, where the one secondary carrier among the firstsecondary carriers is one of the following secondary carriers: asecondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest or highest frequency,and a secondary carrier of the minimum or maximum index value. Thenetwork-side device may configure a secondary carrier for the UE throughsignaling.

In the case that the network-side device configures a secondary carrierthrough signaling, specifically, the network-side device may determine,according to loads of ACK/NACK resources on different carriers and soon, a secondary carrier for the UE to feed back the ACK/NACK, andconfigures the determined secondary carrier for the UE through RRCsignaling or physical-layer signaling (such as PDCCH). More generally,for carrier aggregation of different bands, the network-side device mayconfigure a secondary carrier on each band for the UE to feed back theACK/NACK, or the network-side device configures a secondary carrier forthe UE on every band except the band of the primary carrier of the UE,where the secondary carrier is used for the UE to feed back theACK/NACK. At the time of feeding back the ACK/NACK, when a subframecorresponding to the time on the carrier of only one band is an uplinksubframe, but subframes corresponding to the time on carriers of otherbands are all downlink subframes, the ACK/NACK is fed back on asecondary carrier configured on a band where the subframe at the time isan uplink subframe; at the time of feeding back the ACK/NACK, whensubframes corresponding to the time on the carriers of two or more bandsare uplink subframes, the ACK/NACK is fed back on a secondary carrierconfigured on a band (for example, predetermined by a standard, forexample, a band of a low frequency, or a band of which the network sidenotifies the UE through signaling, or a band of the highest priorityselected according to priorities of bands) where the subframe at thetime is an uplink subframe, or the ACK/NACK is fed back on a specificsecondary carrier (such as a configured secondary carrier of the highestpriority) among secondary carriers where the subframes at the time areuplink subframes, or the ACK/NACK is fed back on a secondary carrierconfigured on at least two bands where the subframes at the time areuplink subframes.

If there are two or more first secondary carriers, and the ACK/NACKchannel resource is carried in the first uplink subframe of thesecondary carrier of the highest priority among the first secondarycarriers, the method further includes:

determining the priority of each secondary carrier among the firstsecondary carriers according to the load of the ACK/NACK correspondingto the first uplink subframe on each secondary carrier where the firstuplink subframe is an uplink subframe, or the frequency of eachsecondary carrier, or the index configuration of each secondary carrier;

or determining priorities for secondary carriers configured for the UE,which specifically includes: for each time, determining priorities forall secondary carriers where a subframe corresponding to the time is anuplink subframe, and determining priorities of secondary carriers amongthe first secondary carriers, which specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink frame.

Preferably, the determining the priorities for the secondary carriersconfigured for the UE may be: if a subframe at the time on the primarycarrier is an uplink subframe, the priority of the primary carrier maybe set to the highest. In addition, the priority may be predefinedaccording to some information, for example, the priority is setaccording to a carrier identifier. In this case, both the network-sidedevice and the UE may determine the priority of the carrier. Thepriority may also be set by the network-side device, and then configuredfor the UE through signaling, where the signaling may be RRC (RadioResource Control, radio resource control) dedicated signaling, or PDCCHinformation. If the network-side device configures a priority for the UEthrough PDCCH information, the network-side device may implicitlydetermine the priority through a bit, scrambling code, or some existingfields in the PDCCH, for example, use a resource allocation field indownlink scheduling in the PDCCH, and determine the priority accordingto the number of allocated resources indicated by the resourceallocation field, for example, set the highest priority for the carrierthat has the most allocated resources. For example, subframe 3 is adownlink subframe for the primary carrier, and subframe 3 is an uplinksubframe for two secondary carriers. Therefore, for subframe 3,priorities may be set for two secondary carriers; if the number ofallocated resources in subframe 3 on secondary carrier 1 is greater thanthat on secondary carrier 2, the priorities of carriers for subframe 3may be set as follows: the priority of secondary carrier 1 is higherthan that of secondary carrier 2.

After the network-side device determines that the ACK/NACK channelresource corresponding to the PDSCH is located on the secondary carrier,the network-side device may further transmit information about thedetermined secondary carrier to the UE through PDCCH information.

When the network-side device schedules only one secondary carrier forthe UE and does not schedule a primary carrier, the secondary carrier isa second secondary carrier. Correspondingly, when the network-sidedevice transmits a piece of PDCCH information to the UE, the ACK/NACKchannel resource is carried in a first uplink subframe on the secondsecondary carrier.

The identifier of a control channel element CCE occupied by the PDCCHcorresponds to the ACK/NACK channel resource; the PDCCH informationindicates scheduling information of a physical downlink shared channelPDSCH carried by the downlink subframe, including: indicating theACK/NACK channel resource by using the identifier of a CCE among theCCEs occupied by the PDDCH. The method is referred to as an implicitindicating method, and is applicable to the case that the network-sidedevice schedules only one secondary carrier for the UE and does notschedule a primary carrier.

The method further includes: reserving, by the network-side device, anACK/NACK resource set for the UE in a subframe used for ACK/NACKfeedback, where at least one ACK/NACK channel resource included in theACK/NACK resource set is located on one or multiple secondary carriers,and each ACK/NACK channel resource in the ACK/NACK resource set iscarried on a unique secondary carrier; the indicating, by the PDCCHinformation, the ACK/NACK channel resource corresponding to the PDSCH,includes: using, by the network-side device, the TPC (Transmit PowerControl, transmit power control) or DAI (Downlink Assignment Index,downlink assignment index) in the PDCCH information transmitted to theUE as an ARI (ACK/NACK Resource Indicator, ACK/NACK channel resourceindicator), where the ARI is used to indicate an ACK/NACK channelresource used for the UE to feed back the ACK/NACK, and the carriercarrying the ACK/NACK channel resource is a carrier used for the UE tofeed back the ACK/NACK. The method is referred to as an explicitindicating method, and is applicable to the case that multiple carriersare scheduled in a downlink subframe.

Correspondingly, the UE receives the RRC dedicated signaling transmittedby the network-side device, and obtains, according to the RRC dedicatedsignaling, an ACK/NACK resource set that is reserved by the network-sidedevice for the UE in a subframe used for ACK/NACK feedback, where atleast one ACK/NACK channel resource included in the ACK/NACK resourceset is located on one or multiple secondary carriers, and each ACK/NACKchannel resource in the ACK/NACK resource set is carried on a uniquesecondary carrier.

In step S22, the determining, according to scheduling information, anACK/NACK channel resource corresponding to the PDSCH, includes:

obtaining, by the UE, the TPC or DAI that is included in the PDCCHinformation transmitted by the network-side device and is used as anACK/NACK channel resource indicator ARI, and determining, according tothe ARI, an ACK/NACK channel resource that is included in the ACK/NACKresource set and is used for the UE to feed back the ACK/NACK, where thecarrier carrying the ACK/NACK channel resource is a carrier used for theUE to feed back the ACK/NACK.

The obtaining, by the UE, the TPC or DAI that is used as an ACK/NACKchannel resource indicator ARI, includes:

selecting, by the UE, one of the secondary carriers where the firstuplink subframe corresponds to an uplink subframe, as a third secondarycarrier; using a TPC command word in the PDCCH information correspondingto the PDSCH carried on the third secondary carrier as a TPC commandword; using a TPC command word in the PDCCH information corresponding toother PDSCHs as an ARI, where the other PDSCHs are carried on one ormultiple secondary carriers among other secondary carriers than thethird secondary carrier, and ARI values are the same when the otherPDSCHs are carried on multiple secondary carriers.

Using FIG. 3 as an example, the ACK/NACK in subframe 2 is for downlinkscheduling of two CCs, namely, a primary carrier and a secondarycarrier. Therefore, the ARI may dynamically indicate that the ACK/NACKis fed back on the primary carrier or secondary carrier. Thereby,ACK/NACK loads on multiple CCs may be adjusted dynamically, so thatACK/NACK loads are balanced. The ACK/NACK in subframes 3, 4, and 7 isonly for downlink scheduling of one CC, and each CC may feed back theACK/NACK. Therefore, the network-side device may use the ACK/NACKresource corresponding to the PDCCH implicit indication. Compared withthe conventional mechanism where scheduling of the primary carrier usesthe ACK/NACK resource corresponding to the PDCCH implicit indication,scheduling of the secondary carrier needs to use the ACK/NACK resourcecorresponding to the ARI explicit indication. In this embodiment, fordownlink scheduling of one CC, scheduling of only one secondary carriermay also use the ACK/NACK resource corresponding to the PDCCH implicitindication, thereby saving signaling resource overheads.

The using, by the network-side device, the TPC in the PDCCH informationas an ARI, includes: selecting, by the network-side device, one of thesecondary carriers where the first uplink subframe corresponds to anuplink subframe, as a third secondary carrier, where the third secondarycarrier is a secondary carrier of the highest priority among thesecondary carriers where the first uplink subframe corresponds to anuplink subframe; scheduling a TPC command word in the PDCCH informationcorresponding to the PDSCH carried on the third secondary carrier as aTPC command word; and scheduling a TPC command word in the PDCCHinformation corresponding to other PDSCHs as an ARI, where the otherPDSCHs are carried on one or multiple secondary carriers among othersecondary carriers than the third secondary carrier, and ARI values arethe same when the other PDSCHs are carried on multiple secondarycarriers.

Further, if the PDCCH is a PDCCH that schedules at least two carriersexcept the carrier of the highest priority, at least two ARIs in thePDCCH may indicate, based on a same or different ACK/NACK resource sets,that the ACK/NACK resource is located on a carrier of at least twocarriers.

Specifically, the ARI in the PDCCH may indicate, based on a sameACK/NACK resource set, the ACK/NACK resource, for example, ARI1 in thePDCCH scheduling secondary carrier 1 and ARI1 in the PDCCH schedulingsecondary carrier 2, to indicate the ACK/NACK resource in an ACK/NACKresource set, thereby saving overheads reserved for the ACK/NACKresource.

The ARI in the PDCCH may also be an indication based on differentACK/NACK resource sets. In this embodiment, a priority may be set foreach carrier, and the carrier of the highest priority is set to thefirst carrier, and other carriers are second carriers.

For example, it is assumed that: three carriers Pcell, Scell1, andScell2 are configured for the UE; subframe n is an uplink subframe forall the three carriers; priorities are set as follows: The priority ofthe Pcell is higher than the priority of Scell1 and higher than thepriority of Scell2, where subframe n is used to feed back the ACK/NACKcorresponding to the PDSCH scheduled in subframe p, and subframe p is andownlink subframe for all the three carriers. If the network-side deviceschedules the three carriers for the UE in downlink subframe p, the UEfeeds back, on the resource indicated by ARI1 in PDCCH1 that schedulesScell1, three ACKs/NACKs corresponding to downlink subframe p of thethree carriers; if the UE leaves PDCCH1 undetected, the UE feeds back,on the resource indicated by the ARI2 in the PDCCH2 that schedulesScell2, two ACKs/NACKs corresponding to downlink subframe p of the Pcelland Scell2. The network-side device learns, through blind detection forthe ACK/NACK resource indicated by ARI1 and ARI2, that the UE leavesPDCCH1 undetected and detects only two pieces of ACK/NACK information onthe ACK/NACK resource. Because the network-side device considers thatthe UE does not receive the PDCCH1 and considers that the UE may notfeed back the ACK/NACK corresponding to the PDCCH1, the ACK/NACKdetection performance is improved due to decrease of the detectedACK/NACK bits. If the network-side device schedules only the Pcell andScell2 for the UE in downlink subframe p, the UE feeds back two ACK/NACKresources corresponding to downlink subframe p of the Pcell and Scell2on the resource indicated by ARI2 of the PDCCH2 that schedules Scell2,and the network-side device detects, directly on the ACK/NACK resourceindicated by ARI2, only the two pieces of ACK/NACK informationcorresponding to the Pcell and Scell2, thereby improving detectionperformance. If the network-side device schedules only the Pcell andScell for the UE in downlink subframe p, the UE feeds back, on theresource indicated by ARI1 of the PDCCH1 that schedules Scell1, threeACK/NACK resources corresponding to downlink subframe p of the Pcell,Scell1, and Scell2, and the network-side device detects, directly on theACK/NACK resource indicated by ARI1, the two pieces of ACK/NACKinformation corresponding to the Pcell and Scell1. Therefore, in thiscase, the UE is unable to learn whether it is that the network-sidedevice schedules Scell2 whereas the UE leaves PDCCH2 undetected, or itis that the network-side device does not schedule Scell2 at all.

The method further includes: determining priorities for secondarycarriers configured for the UE, where the determining includes: for eachtime, determining priorities for all secondary carriers where a subframecorresponding to the time is an uplink subframe.

The determining priorities for all secondary carriers where a subframecorresponding to the time is an uplink subframe includes: according tothe load of the ACK/NACK on each secondary carrier where the subframe isan uplink subframe, or the frequency of each secondary carrier, or theindex configuration of each secondary carrier.

In this embodiment, the network-side device indicates, through PDCCHinformation, that the ACK/NACK channel resource corresponding to thePDSCH is carried in the first uplink subframe on the secondary carrierand that a subframe of the same time as the first uplink subframe is adownlink subframe on the primary carrier, so that the UE feeds back, onthe ACK/NACK channel resource in the first uplink subframe of thedetermined secondary carrier, the ACK/NACK corresponding to the PDSCH,so that the ACK/NACK can also be fed back when carriers of differentuplink and downlink subframe configurations are aggregated.

For Embodiment 1, in brief,

for the method for receiving acknowledgement or negative indicationinformation in the time-division duplex TDD system, the specificimplementation on the network-side device may include:

configuring, by a network-side device, at least two carriers for a userequipment UE, where the carriers include one primary carrier and atleast one secondary carrier;

transmitting, by the network-side device, physical downlink controlchannel PDCCH information to the UE in a downlink subframe, where thePDCCH information indicates scheduling information of a physicaldownlink shared channel PDSCH carried in a downlink subframe; the PDCCHinformation indicates an acknowledgement ACK or negative acknowledgementNACK channel resource corresponding to the PDSCH, where the ACK/NACKchannel resource is carried in a first uplink subframe of a secondarycarrier, where the first uplink subframe is determined according to atiming relationship between the PDSCH and the ACK/NACK corresponding tothe PDSCH, and a subframe of the same time as the first uplink subframeis a downlink subframe on the primary carrier; and

receiving, by the network-side device, in the first uplink subframe ofthe secondary carrier carrying the ACK/NACK channel resource, theACK/NACK fed back by the UE.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one first secondary carrier, the ACK/NACK channel resourceis carried in the first uplink subframe of the first secondary carrier;

and/or,

if there are two or more first secondary carriers, the ACK/NACK channelresource is carried in the first uplink subframe of one secondarycarrier among the first secondary carriers.

The one secondary carrier among the first secondary carriers is one ofthe following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

If there are two or more first secondary carriers, and the ACK/NACKchannel resource is carried in the first uplink subframe of onesecondary carrier among the first secondary carriers,

the method further includes:

determining priorities of secondary carriers among the first secondarycarriers according to the load of the ACK/NACK corresponding to thefirst uplink subframe on each secondary carrier where the first uplinksubframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier;

or, the method further includes:

determining priorities for secondary carriers configured for the UE,where the determining includes: for each time, determining prioritiesfor all secondary carriers where a subframe corresponding to the time isan uplink subframe; and

determining priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink subframe.

After the network-side device determines that the ACK/NACK channelresource corresponding to the PDSCH is located on the secondary carrier,the method further includes:

sending information about the determined secondary carrier to the UEthrough the PDCCH information.

When the network-side device schedules only one secondary carrier forthe UE and does not schedule a primary carrier, the secondary carrier isa second secondary carrier. Correspondingly, when the network-sidedevice transmits a piece of PDCCH information to the UE, the ACK/NACKchannel resource is carried in a first uplink subframe on the secondsecondary carrier.

Correspondingly, the identifier of the control channel element CCEoccupied by the PDCCH corresponds to the ACK/NACK channel resource;

the indicating, by the PDCCH information, scheduling information of aphysical downlink shared channel PDSCH that is carried by the downlinksubframe, includes:

indicating the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

The method further includes: reserving, by the network-side devicethrough radio resource control RRC dedicated signaling, an ACK/NACKresource set for the UE in a subframe used for ACK/NACK feedback, whereat least one ACK/NACK channel resource included in the ACK/NACK resourceset is located on one or multiple secondary carriers, and each ACK/NACKchannel resource in the ACK/NACK resource set is carried on a uniquesecondary carrier;

the indicating, by the PDCCH information, the ACK/NACK channel resourcecorresponding to the PDSCH, includes:

using, by the network-side device, the transmit power control TPC ordownlink assignment index DAI in the PDCCH information transmitted tothe UE as an ACK/NACK channel resource indicator ARI, where the ARI isused to indicate an ACK/NACK channel resource that is included in theACK/NACK resource set and used for the UE to feed back the ACK/NACK, andthe carrier carrying the ACK/NACK channel resource is a carrier used forthe UE to feed back the ACK/NACK.

Correspondingly, the using, by the network-side device, the TPC in thePDCCH information as an ARI, includes:

selecting, by the network-side device, one of the secondary carrierswhere the first uplink subframe corresponds to an uplink subframe, as athird secondary carrier;

scheduling a TPC command word in the PDCCH information corresponding tothe PDSCH carried on the third carrier as a TPC command word;

scheduling a TPC command word in the PDCCH information corresponding toother PDSCHs as an ARI, where the other PDSCHs are carried on one ormultiple secondary carriers among other secondary carriers than thethird secondary carrier, and the ARI values are the same when the otherPDSCHs are carried on multiple secondary carriers.

Correspondingly, the method further includes:

determining priorities for secondary carriers configured for the UE,where the determining includes: for each time, determining prioritiesfor all secondary carriers where a subframe corresponding to the time isan uplink subframe;

the third secondary carrier is a secondary carrier of the highestpriority among the secondary carriers where the first uplink subframecorresponds to an uplink subframe.

Correspondingly, the determining priorities for all secondary carrierswhere a subframe corresponding to the time is an uplink subframeincludes:

according to the load of the ACK/NACK on each secondary carrier wherethe subframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier.

For the method for transmitting acknowledgement or negativeacknowledgement indication information in the time-division duplex TDDsystem according to this embodiment, the specific implementation on theUE side may include:

receiving, by a user equipment UE, physical downlink control channelPDCCH information transmitted by a network-side device to the UE in adownlink subframe;

determining, by the UE according to scheduling information carried inthe PDCCH information, a physical downlink shared channel PDSCHscheduled by the PDCCH information; determining, according to the PDCCHinformation, an acknowledgement ACK or negative acknowledgement NACKchannel resource corresponding to the PDSCH; determining, according to atiming relationship between the PDSCH and the ACK/NACK corresponding tothe PDSCH, a first uplink subframe used for feeding back the ACK/NACK,where a subframe of the same time as the first uplink subframe is adownlink subframe on a primary carrier; and determining a secondarycarrier carrying the ACK/NACK channel resource;

feeding back, by the UE on the determined ACK/NACK channel resource, theACK/NACK corresponding to the PDSCH, where the ACK/NACK channel resourceis located in the first uplink subframe of the determined secondarycarrier.

The method further includes: receiving, by the UE, radio resourcecontrol RRC dedicated signaling transmitted by the network-side device,and obtaining, according to the RRC dedicated signaling, an ACK/NACKresource set that is reserved by the network-side device for the UE in asubframe used for ACK/NACK feedback, where at least one ACK/NACK channelresource included in the ACK/NACK resource set is located on one ormultiple secondary carriers, and each ACK/NACK channel resource in theACK/NACK resource set is carried on a unique secondary carrier;

the determining, according to the PDCCH information, the ACK/NACKchannel resource corresponding to the PDSCH, includes:

obtaining, by the UE, the transmit power control TPC or downlinkassignment index DAI that is included in the PDCCH informationtransmitted by the network-side device and is used as an ACK/NACKchannel resource indicator ARI, and determining, in the ACK/NACKresource set according to the ARI, the ACK/NACK channel resource usedfor the UE to feed back the ACK/NACK, where the carrier carrying theACK/NACK channel resource is a carrier used for the UE to feed back theACK/NACK.

Correspondingly, the obtaining, by the UE, the TPC or DAI that is usedas the ACK/NACK channel resource indicator ARI, includes:

selecting, by the UE, one of the secondary carriers where the firstuplink subframe corresponds to an uplink subframe, as a third secondarycarrier;

using a TPC command word in the PDCCH information corresponding to thePDSCH carried on the third carrier as a TPC command word; and

using a TPC command word in the PDCCH information corresponding to otherPDSCHs as an ARI, where the other PDSCHs are carried on one or multiplesecondary carriers among other secondary carriers than the thirdsecondary carrier, and the ARI values are the same when the other PDSCHsare carried on multiple secondary carriers.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one first secondary carrier, the determining a secondarycarrier carrying the ACK/NACK channel resource includes: determining thesecondary carrier carrying the ACK/NACK channel resource as the firstsecondary carrier;

and/or,

if there are two or more first secondary carriers, the determining asecondary carrier carrying the ACK/NACK channel resource includes:determining the secondary carrier carrying the ACK/NACK channel resourceas one first secondary carrier among the first secondary carriers;

The one secondary carrier among the first secondary carriers is one ofthe following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

Correspondingly, if there are two or more first secondary carriers, andthe secondary carrier carrying the ACK/NACK channel resource is asecondary carrier of the highest priority among the first secondarycarriers,

the method further includes:

determining priorities of secondary carriers among the first secondarycarriers according to the load of the ACK/NACK corresponding to thefirst uplink subframe on each secondary carrier where the first uplinksubframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier;

or, the method further includes:

determining priorities for secondary carriers configured for the UE,where the determining specifically includes: for each time, determiningpriorities for all secondary carriers where a subframe corresponding tothe time is an uplink subframe; and

determining priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink subframe.

The determining a secondary carrier carrying the ACK/NACK channelresource includes:

if the network-side device schedules only one secondary carrier and doesnot schedule a primary carrier for the UE, and the secondary carrier isa second secondary carrier, determining, by the UE, the second secondarycarrier as the secondary carrier carrying the ACK/NACK channel resource.

Correspondingly, the identifier of the control channel element CCEoccupied by the PDCCH corresponds to the ACK/NACK channel resource;

the determining, according to the indication of the PDCCH information,the ACK/NACK channel resource corresponding to the PDSCH, includes:

determining the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

Embodiment 2

This embodiment provides a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD system orsimilar system. As shown in FIG. 4, this method may be executed by anetwork-side device, and specifically includes:

S31. A network-side device configures at least two carriers for a UE,where the carriers include one primary carrier and at least onesecondary carrier.

S32. The network-side device transmits PDCCH information to the UE in adownlink subframe, where the PDCCH information indicates schedulinginformation of a PDSCH carried in a downlink subframe.

S33. Determine at least two different ACK/NACK channel resourcesaccording to at least two timing relationships between the PDSCH and theACK/NACK corresponding to the PDSCH.

S34. Determine a first channel resource from the at least two differentACK/NACK channel resources and use the first channel resource for the UEto feed back the ACK/NACK.

S35. Notify the UE of the first channel resource through signaling.

S36. Receive the ACK/NACK fed back by the UE on the first channelresource.

The method for transmitting acknowledgement or negative acknowledgementindication information in a TDD system according to this embodiment maybe shown in FIG. 5; the method may also be executed by a UE, andspecifically includes:

S41. A UE receives PDCCH information transmitted by a network-sidedevice to the UE in a downlink subframe, where the PDCCH informationindicates scheduling information of a PDSCH carried in a downlinksubframe.

S42. The UE receives information about a first channel resource of whichthe network-side device notifies through signaling and which is used forthe UE to feed back an ACK/NACK, where the first channel resource isdetermined by the network-side device from at least two differentACK/NACK channel resources that are determined by the network-sidedevice according to at least two timing relationships between the PDSCHand the ACK/NACK corresponding to the PDSCH.

S43. The UE feeds back the ACK/NACK corresponding to the PDSCH to thenetwork-side device on the first channel resource.

The at least two timing relationships include at least timingrelationships that correspond to different carriers and/or correspond todifferent uplink subframes on a same carrier.

The at least two different ACK/NACK channel resources include: ACK/NACKchannel resources carried in uplink subframes of different carriers atthe same time, and/or, ACK/NACK channel resources in different uplinksubframes. Specifically, the ACK/NACK channel resources in differentuplink subframes may be different uplink subframes on different carriersor different uplink subframes on a same carrier.

Specifically, in step S34, the determining a first channel resource fromthe at least two different ACK/NACK channel resources includes:

selecting, according to loads of at least two different ACK/NACK channelresources, an ACK/NACK channel resource that has a lightest load, as afirst channel resource;

or, selecting, according to delays of at least two different ACK/NACKchannel resources, an ACK/NACK channel resource that has a shortestdelay, as a first channel resource;

or, determining, according to loads and delays of at least two differentACK/NACK channel resources, a first channel resource from the at leasttwo different ACK/NACK channel resources.

In step S35, the notifying the first channel resource to the UE throughsignaling includes one of the following:

notifying the UE of information about the first channel resource throughan added bit of the PDCCH information, a TPC, or a DAI;

determining, according to a mapping relationship between a scramblingcode and the ACK/NACK channel resource, a first scrambling codecorresponding to the first channel resource, and notifying the firstscrambling code to the UE through PDCCH information; and

determining, according to a mapping relationship between a PDCCHtime-frequency resource position and the ACK/NACK channel resource, afirst PDCCH time-frequency resource position corresponding to the firstchannel resource, and notifying the UE of the first PDCCH time-frequencyresource position through PDCCH information.

Correspondingly, in step S42, the receiving, by the UE, informationabout a first channel resource of which the network-side device notifiesthrough signaling and which is used for the UE to feed back an ACK/NACK,includes one of the following:

receiving, by the UE, a first channel resource that is used for the UEto feed back the ACK/NACK and of which the network-side device notifiesthrough an added bit of the PDCCH information, a TPC, a DAI, a firstscrambling code corresponding to the first channel resource, or a firstPDCCH time-frequency resource position corresponding to the firstchannel resource.

The signaling may be physical layer signaling (such as PDCCHinformation), or RLC (Radio Link Control, radio link control) layersignaling, or MAC (Media Access Control, media access control) layersignaling, or RRC (Radio Resource Control, radio resource control) layersignaling.

According to the method provided by this embodiment, the ACK/NACK of thesecondary carrier may be adjusted to the ACK/NACK resource of theprimary carrier for feedback, and the ACK/NACK of the primary carriermay also be adjusted to the ACK/NACK resource of the secondary carrierfor feedback, which are described respectively through examples.

In the case that the ACK/NACK of the secondary carrier may be adjustedto the ACK/NACK resource of the primary carrier for feedback:

As shown in FIG. 6, the ACKs/NACKs corresponding to downlink subframes 0and 9, in subframe 7 of the secondary carrier may be adjusted to theprimary carrier for feedback, and may be adjusted, according to thetiming relationship of the primary carrier, to subframe 4 of the primarycarrier for feedback. Using PDCCH adjustment as an example, thenetwork-side device may use a special value of the DAI (for example, theDAI is equal to 4) or a state of the TPC in the PDCCH scheduled in thedownlink subframes 0 and 9 to indicate that the ACKs/NACKs correspondingto downlink subframes 0 and 9, in subframe 7 of the secondary carrierare adjusted to subframe 4 of the primary carrier for feedback;meanwhile, the ACK/NACK resource may be indicated by the TPC in thePDCCH, or an extra ACK/NACK resource is reserved separately for thehandover, where the extra resource is a resource outside the resourceset indicated by the ARI.

The above adjusting method reduces the ACK/NACK load and feedback delayon subframe 7 of the secondary carrier. Specifically, if the ACKs/NACKscorresponding to subframes 0 and 9 are fed back in subframe 7 of thesecondary carrier, the feedback delays are 7 and 8 respectively; afterthe adjusting, the feedback delays are 4 and 5 respectively.

In the case that the ACK/NACK of the primary carrier may be adjusted tothe ACK/NACK resource of the secondary carrier for feedback:

As shown in FIG. 6, the ACK/NACK corresponding to downlink subframe 1,in subframe 2 of the primary carrier may be adjusted to the primarycarrier for feedback, and may be adjusted, according to the timingrelationship of the secondary carrier, to subframe 7 of the secondarycarrier for feedback. Using PDCCH adjustment as an example, thenetwork-side device may use a special value of the DAI (for example, theDAI is equal to 4) or a state of the TPC in the PDCCH scheduled bydownlink subframe 1 to indicate that the ACK/NACK corresponding todownlink subframe 1, in subframe 2 of the primary carrier is adjusted tosubframe 7 of the secondary carrier for feedback; meanwhile, theACK/NACK resource may be indicated by the TPC (or DAI) in the PDCCH, oran extra ACK/NACK resource is reserved separately for the handover,where the extra resource is a resource outside the resource setindicated by the ARI.

In this embodiment, the network-side device configures at least twocarriers for the UE, where the carriers includes one primary carrier andat least one secondary carrier; transmits PDCCH information to the UE ina downlink subframe, where the PDCCH information indicates schedulinginformation of a PDSCH carried by a downlink subframe; determines atleast two different ACK/NACK channel resources according to at least twotiming relationships between the PDSCH and the ACK/NACK corresponding tothe PDSCH; determines a first channel resource from the at least twodifferent ACK/NACK channel resources and uses the first channel resourcefor the UE to feed back the ACK/NACK; notifies the first channelresource to the UE through signaling; and receives the ACK/NACK fed backby the UE on the first channel resource. Therefore, the ACK/NACK canalso be fed back when carriers of different uplink and downlink subframeconfigurations are aggregated. In addition, the loads of ACKs/NACKs oncarriers may be balanced, and the ACK/NACK feedback delay may bereduced.

The embodiment of the present invention also provides a method fortransmitting acknowledgement or negative acknowledgement indicationinformation. This embodiment is applicable to a TDD system, an FDDsystem, and a system where TDD and FDD carriers are aggregated.

As shown in FIG. 16, this method may be executed by a network-sidedevice, and specifically includes:

S161. A network-side device configures at least two carriers for a UE,where the carriers include one primary carrier and at least onesecondary carrier.

The primary carrier may use one of the FDD and TDD duplex modes; nomatter whether the primary carrier is a carrier of the FDD or TDD duplexmode, the secondary carrier may use one of the FDD and TDD duplex modes.Of course, the primary carrier and secondary carrier may also be acarrier of other modes, which is not limited here, so long as thesolution of the present invention can be implemented. In addition, theprimary carrier in the present invention may be a carrier for the UE toindependently access, or a carrier for the UE in an idle state to campon, or a carrier for the UE to perform radio link failure detection; theprimary carrier in the present invention may also be a carrier thatcannot provide independent access for the UE but can only be used whenthe UE is in a connected state.

S162. The network-side device transmits PDCCH information to the UE in afirst downlink subframe, where the PDCCH information indicatesscheduling information of a PDSCH carried in a second downlink subframe.

The first downlink subframe and the second downlink subframe may be thesame subframe or may also be different subframes. The first downlinksubframe and the second downlink subframe may be on the same carrier ormay also be on different carriers, where the latter is also referred toas cross-carrier scheduling.

The PDCCH may be a PDCCH demodulated based on a cell-specific referencesignal in an LTE system, or may also be an enhanced PDCCH demodulatedbased on a cell-specific reference signal in the LTE system.

S163. Select one of at least two timing relationships between thesubframe carrying the PDSCH and a subframe carrying an ACK/NACKcorresponding to the PDSCH, as a first timing relationship; anddetermine a third uplink subframe corresponding to the first timingrelationship and used for the UE to transmit the ACK/NACK correspondingto the PDSCH.

On a first carrier corresponding to the first timing relationship, asubframe of the same time as the second downlink subframe is a downlinksubframe, and this may be called a first condition. Thereby, it can beensured that the determined third uplink subframe is a subframe that canbe used for the UE to feed back the ACK/NACK.

Specifically, the at least two timing relationships may include timingrelationships corresponding to different carriers; and/or, includetiming relationships corresponding to a same carrier. In this case, withrespect to different timing relationships, uplink subframescorresponding to the downlink subframes on the carrier and used forACK/NACK feedback are different.

In the case that at least two timing relationships correspond todifferent carriers, for example, the timing relationships between thesubframe carrying the PDSCH and the subframe carrying the ACK/NACK maybe (n, n+4), that is, if the UE receives the PDSCH in subframe n, the UEfeeds back the ACK/NACK corresponding to the PDSCH in subframe n+4; thetiming relationship in the TDD carrier may be indicated by (n, n+k),where k may be greater than or equal to 4, because the fourth subframeafter the PDSCH may be not an uplink subframe for the TDD system.Particularly, ensuring that k is greater than or equal to 4 takes theprocessing delay of the PDSCH into account, and in the future, othervalues may also be used.

In the case that at least two timing relationships correspond to a samecarrier, assuming that a downlink subframe on a carrier carries a PDSCH,the ACK/NACK corresponding to the PDSCH may be not only fed back in anuplink subframe of the carrier, but also fed back in another uplinksubframe of the carrier, where the different uplink subframes correspondto different timing relationships. The carrier may be a TDD carrier, oran FDD carrier, or other carriers.

The selecting a timing relationship may be implemented in multiplemanners, for example, random selection, and the timing relationship mayalso be selected according to different carriers corresponding to thetiming relationships or different uplink subframes used for ACK/NACKfeedback. Of course, the selected first timing relationship first needsto satisfy the condition: on a first carrier corresponding to the firsttiming relationship, a subframe of the same time as the second downlinksubframe is a downlink subframe.

Specifically, if the timing relationships correspond to differentcarriers, a timing relationship corresponding to a carrier that has thelightest load may be selected according to the loads of the ACK/NACKchannels on the carriers; or a timing relationship corresponding to acarrier that has the shortest feedback delay may be selected accordingto the ACK/NACK feedback delay on the carriers; or a timing relationshipcorresponding to a carrier where transmit power required by the UE isthe lowest may be selected. In the case that selection is performedaccording to transmit power, assuming that the UE is far from a macrocell carrying the primary carrier but is near to a micro cell carryingthe secondary carrier, the network-side device may select the timingrelationship corresponding to the secondary carrier for the UE, becausethe transmit power required by the UE when the secondary carrier isselected is lower than the transmit power required by the UE when theprimary carrier is selected. Of course, the following may also beconsidered comprehensively: load, feedback delay, and transmit power.

If the timing relationships correspond to a same carrier, it isnecessary to consider different uplink subframes corresponding to timingrelationships on the carrier. Specifically, according to loads ofACK/NACK channels in different uplink subframes, a timing relationshipcorresponding to an uplink subframe that has the lightest load may beselected; or according to the ACK/NACK feedback delay in the uplinksubframes, a timing relationship corresponding to an uplink subframethat has the shortest feedback delay may be selected. Of course, thefollowing may also be considered comprehensively: load and feedbackdelay.

For the determining a third uplink subframe in the above step, a thirduplink subframe used for the UE to send an ACK/NACK corresponding to thePDSCH may be determined according to the first timing relationship andthe subframe carrying the PDSCH, namely, the second downlink subframe.

S164. Determine a first carrier used for the UE to transmit the ACK/NACKcorresponding to the PDSCH.

After the first timing relationship is determined, the first carrier maybe determined according to the first timing relationship. Specifically,no matter whether different timing relationships correspond to differentcarriers or different timing relationships correspond to a same carrier,the first carrier corresponding to the first timing relationship may bedetermined according to the mapping relationships between timingrelationships and carriers.

Steps S163 and S164 may also be implemented in another manner, that is,first determining the first carrier, and then determining thecorresponding first timing relationship according to the determinedfirst carrier. Specifically:

S163′. Determine a first carrier used for the UE to transmit theACK/NACK corresponding to the PDSCH.

If different timing relationships correspond to different carriers, acarrier may be selected randomly as a first carrier. Or a carrier thathas the lightest load may be selected as a first carrier according toloads of ACK/NACK channels in the carriers; or a carrier that has theshortest feedback delay is selected as a first carrier according to theACK/NACK feedback delays in the carriers; or a carrier where transmitpower required by the UE is the lowest is selected as a first carrier.Of course, the following may also be considered comprehensively: load,feedback delay, and transmit power.

When the first carrier is determined, it is necessary to guarantee thatthe timing relationship corresponding to the selected carrier meets thecondition that on a first carrier corresponding to the timingrelationship, a subframe of the same time as the second downlinksubframe is a downlink subframe, so that it may be ensured that thedetermined third uplink subframe is a subframe that can be used for theUE to feed back the ACK/NACK.

S164′. Select one of at least two timing relationships between thesubframe carrying the PDSCH and a subframe carrying an ACK/NACKcorresponding to the PDSCH, as a first timing relationship; anddetermine a third uplink subframe corresponding to the first timingrelationship and used for the UE to transmit the ACK/NACK correspondingto the PDSCH.

For the above processing of selecting one timing relationship as a firsttiming relationship, if different timing relationships correspond todifferent carriers, the timing relationship corresponding to the firstcarrier may be determined according to the first carrier determined instep S163′. Afterward, a third uplink subframe used for the UE totransmit the ACK/NACK corresponding to the PDSCH may be determinedaccording to the first timing relationship and the subframe carrying thePDSCH, namely, the second downlink subframe.

If different timing relationships correspond to a same carrier, it isnecessary to consider different uplink subframes corresponding to timingrelationships on the carrier. Specifically, according to loads ofACK/NACK channels in different uplink subframes, a timing relationshipcorresponding to an uplink subframe that has the lightest load may beselected; or according to the ACK/NACK feedback delay on the carriers, atiming relationship corresponding to an uplink subframe that has theshortest feedback delay may be selected. Of course, the following mayalso be considered comprehensively: load and feedback delay. In thiscase, because the first timing relationship is determined according tothe uplink subframe, the uplink subframe used for determining the firsttiming relationship is a third uplink subframe used for the UE totransmit the ACK/NACK corresponding to the PDSCH.

As described in step S163, for step S164′, the selected first timingrelationship also needs to meet the condition that on a first carriercorresponding to the first timing relationship, a subframe of the sametime as the second downlink subframe should be a downlink subframe, sothat it may be ensured that the determined third uplink subframe is asubframe that can be used for the UE to feed back the ACK/NACK.

Correspondingly, when the first carrier or third uplink subframe isselected, if the corresponding first timing relationship cannot meet theabove condition, reselection needs to be performed, so that the firsttiming relationship meets the condition. In other words, when the firstcarrier or third uplink subframe is selected, it is necessary toconsider, at the same time, that the first timing relationship needs tomeet the condition.

S165. Indicate the determined third uplink subframe and the relatedinformation corresponding to the first carrier to the UE.

When the UE learns the first timing relationship selected by thenetwork-side device, the UE correspondingly learns the first carriercorresponding to the first timing relationship, for example, determines,according to the mapping relationships between timing relationships andcarriers, a third uplink subframe used for the UE to transmit theACK/NACK corresponding to the PDSCH. Therefore, the indicating step ofstep S165 may be specifically: indicating the selected first timingrelationship to the UE. That is, related information corresponding tothe third uplink subframe and the first carrier is the first timingrelationship. Specifically, the first timing relationship may beindicated through layer-1 signaling and/or RRC signaling.

If timing relationships correspond to different carriers, thenetwork-side device may indicate only the selected first carrier to theUE. Correspondingly, the UE may determine, according to the firstcarrier, the first timing relationship corresponding to the firstcarrier, and further determine, according to the first timingrelationship, a third uplink subframe used for the UE to transmit theACK/NACK corresponding to the PDSCH. Therefore, the indicating step ofstep S165 may be specifically: indicating the selected first carrier tothe UE. That is, related information corresponding to the third uplinksubframe and the first carrier is the first carrier. Specifically, thefirst carrier may be indicated through layer-1 signaling and/or RRCsignaling.

Of course, related information of the third uplink subframe and thefirst carrier may also be the third uplink subframe and the firstcarrier information. Correspondingly, the network-side device mayindicate the third uplink subframe and the first carrier to the UEthrough layer-1 signaling and/or RRC signaling.

S166. In the third uplink subframe of the determined first carrier,determine a first channel resource used for the UE to feed back theACK/NACK corresponding to the PDSCH, and indicate the first channelresource to the UE.

The first channel resource may be selected randomly, or may also beselected by the network-side device according to channel loads and soon, which is not specifically limited by the present invention.

For the indicating the first channel resource to the UE, specifically,the ACK/NACK channel resource may be indicated to the UE in an implicitindicating manner. For example, the ACK/NACK channel resource mayimplicitly correspond to the identifier of a CCE occupied by the PDCCH.Thereby, the network-side device should receive, on an ACK/NACK channelresource corresponding to a CCE that is used by the network-side deviceto schedule the PDCCH, the ACK/NACK transmitted by the UE.Correspondingly, the UE may determine, according to the CCE thatschedules the PDCCH, a channel resource that corresponds to the CCE andis used for the UE to feed back the ACK/NACK, where the CCE may also bean enhanced CCE corresponding to an enhanced PDCCH.

The ACK/NACK channel resource may also be indicated explicitly throughsignaling, for example, one or a group of ACK/NACK channel resources isreserved through RRC signaling. If one ACK/NACK channel resource isreserved, the network-side device receives, on the channel resource, theACK/NACK transmitted by the UE; and correspondingly, the UE may learnthat the reserved channel resource is a channel resource used for the UEto feed back the ACK/NACK. If a group of ACK/NACK channel resources isreserved, the network-side device further needs to dynamically indicate,through the PDCCH, which resource in the group of ACK/NACK channelresources is used as a channel resource for the UE to feed back theACK/NACK; and correspondingly, the UE may learn that the resourcedynamically indicated by the PDCCH in the group of channel resources isa channel resource that may be used for the UE to feed back theACK/NACK; the network-side device needs to receive, on the channelresource dynamically indicated, the ACK/NACK transmitted by the UE.Specifically, the channel resource may be dynamically indicated througha bit or scrambling code in the PDCCH.

It should be noted that the information in the two steps S165 and S166may be indicated by the network-side device to the UE by obtaining asame piece of signaling, or may also be indicated through differentsignaling.

S167. Receive the ACK/NACK fed back by the UE on the first channelresource in the third subframe of the first carrier.

The method for transmitting acknowledgement or negative acknowledgementindication information according to this embodiment may be as shown inFIG. 17; the method may also be executed by a UE, and specificallyincludes:

S171. A UE determines two configured carriers, where the carriersinclude one primary carrier and at least one secondary carrier.

The primary carrier and secondary carrier are specifically the same asthose in step S161, and are not further described here.

S172. The UE receives PDCCH information transmitted by a network-sidedevice to the UE in a first downlink subframe, where the PDCCHinformation indicates scheduling information of a PDSCH carried in asecond downlink subframe.

The relationship between the first downlink subframe and the seconddownlink subframe, and the specific PDCCH, are described as step S162,and are not further described here.

S173. Obtain indication information transmitted by the network-sidedevice to the UE, and determine, according to the indicationinformation, a third uplink subframe that is determined by thenetwork-side device for the UE and is used to feed back the ACK/NACK,and a first carrier.

The indication information is related information corresponding to thethird uplink subframe and the first carrier that are determined by thenetwork-side device for the UE for ACK/NACK feedback. Specifically, theindication information may be sent by the network-side device to the UEthrough layer-1 signaling and/or RRC signaling.

As described in step S165, the related information may be a first timingrelationship selected by the network-side device, or a first carrierdetermined by the network-side device. For the selected first timingrelationship, on a first carrier corresponding to the first timingrelationship, a subframe of the same time as the second downlinksubframe should be a downlink subframe, so that it may be ensured thatthe determined third uplink subframe is a subframe that can be used forthe UE to feed back the ACK/NACK.

If the obtained related information is a first timing relationship, thethird uplink subframe and first carrier are determined according to theindication information, which may specifically include: according to thefirst timing relationship and the subframe carrying the PDSCH, namely,the second downlink subframe, determining a third uplink subframe usedfor the UE to transmit the ACK/NACK corresponding to the PDSCH, anddetermining, according to the mapping relationships between timingrelationships and carriers, and the first timing relationship, a firstcarrier corresponding to the first timing relationship.

If the obtained related information is the first carrier, the thirduplink subframe and the first carrier are determined according to theindication information, which may specifically include: determining, bythe UE according to the first carrier and the mapping relationshipsbetween carriers and timing relationships, a first timing relationshipcorresponding to the first carrier, and then determining a correspondingthird uplink subframe according to the first timing relationship and thesubframe carrying the PDSCH, namely, the second downlink subframe.

S174. Obtain the first channel resource that is indicated by thenetwork-side device to the UE and is used for the UE to feed back theACK/NACK corresponding to the PDSCH.

Corresponding to step S166, the UE may determine the first ACK/NACKchannel resource by receiving layer-1 signaling and/or RRC signaling.Specifically, if the network-side device uses an implicit indicatingmanner, for example, the ACK/NACK channel resource may implicitlycorrespond to the identifier of the CCE occupied by the PDCCH. Thereby,the UE may correspondingly determine that the ACK/NACK channel resourcecorresponding to the CCE or a CCE among the CCEs on which the UEreceives the PDCCH, is the ACK/NACK channel resource configured by thenetwork-side device for the UE, so that the UE can transmit the ACK/NACKon the channel resource. If the network-side device may use a signalingexplicit indicating mode, for example, reserve one or a group ofACK/NACK channel resources, if one ACK/NACK channel resource isreserved, the UE may determine that the channel resource is an ACK/NACKchannel resource configured by the network-side device for the UE, andtherefore, can transmit the ACK/NACK on the channel resource; if a groupof ACK/NACK channel resources is reserved, the UE further needs todynamically obtain, through the PDCCH, which resource in the group ofACK/NACK channel resources is used as a channel resource for currentACK/NACK feedback. Correspondingly, the UE transmits the ACK/NACK on thedynamically obtained channel resource. Specifically, the PDCCH may bedynamically indicated through a bit or scrambling code in the PDCCH.

It should be noted that the information in steps S173 and S174 may beobtained by the UE by obtaining a same piece of signaling or obtainingdifferent signaling.

S175. Send the ACK/NACK corresponding to the PDSCH on the first channelresource in the third uplink subframe of the first carrier.

In addition, in the present invention, the carrier corresponds to theserving cell. Specifically, for the FDD system, a serving cell includesa downlink carrier and an uplink carrier corresponding to the downlinkcarrier; for the TDD system, a serving cell corresponds to a TDDcarrier.

The layer-1 signaling may correspond to the PDCCH.

Specifically, the network-side device may notify the UE of informationabout the first channel resource through an added bit of the PDCCHinformation, a TPC, or a DAI.

or determine, according to a mapping relationship between a scramblingcode and the ACK/NACK channel resource, a first scrambling codecorresponding to the first channel resource, and notify the UE of thefirst scrambling code through PDCCH information;

or determine, according to a mapping relationship between a PDCCHtime-frequency resource position and the ACK/NACK channel resource, afirst PDCCH time-frequency resource position corresponding to the firstchannel resource, and notify the UE of the first PDCCH time-frequencyresource position through PDCCH information.

Correspondingly, the receiving, by the UE, information about a firstchannel resource of which the network-side device notifies throughsignaling and which is used for the UE to feed back an ACK/NACK, mayinclude one of the following:

receiving, by the UE, a first channel resource that is used for the UEto feed back the ACK/NACK and of which the network-side device notifiesthrough an added bit of the PDCCH information, a TPC, a DAI, a firstscrambling code corresponding to the first channel resource, or a firstPDCCH time-frequency resource position corresponding to the firstchannel resource.

The signaling may be physical layer signaling (such as PDCCHinformation), or RLC (Radio Link Control, radio link control) layersignaling, or MAC (Media Access Control, media access control) layersignaling, or RRC (Radio Resource Control, radio resource control) layersignaling.

By using the above implementation solutions, in a system where at leasttwo TDD carriers of different uplink and downlink subframeconfigurations are aggregated or a system where at least one FDD carrierand at least one TDD carrier are aggregated, a network-side deviceselects a first timing relationship from at least two timingrelationships, and on a first carrier corresponding to the first timingrelationship, a subframe of the same time as the second downlinksubframe is a downlink subframe, thereby configuring a subframe, acarrier, and a corresponding channel resource that can be used forACK/NACK feedback for the UE. Therefore, it can be guaranteed that theUE not only can perform ACKK/NACK feedback, but also can performflexible ACK/NACK feedback. In addition, the solutions of the presentinvention are also applicable to a system where at least two TDDcarriers of the same uplink and downlink subframe configurations areaggregated, or a system where at least two FDD carriers are aggregated,or similar systems.

In addition, the above implementation solutions make it possible tochoose to feed back the ACK/NACK in different carriers or differentsubframes of a same carrier. Therefore, the solutions may also balanceACK/NACK feedback loads on all carriers or all subframes. Further, whenthe first timing relationship or first carrier is selected according tothe ACK/NACK feedback delay, the ACK/NACK feedback delay may be furtherreduced. In addition, in a scenario where the network-side devicetransmits different carriers at different geographic locations, forexample, a macro base station corresponds to a carrier and a micro basestation corresponds to another carrier, the network-side device mayselect a carrier where the transmit power needed by the UE is low, forthe UE to perform ACK/NACK feedback, thereby reducing power consumptionof the UE and improving performance of the network-side device inreceiving the ACK/NACK.

According to the method provided by this embodiment, the ACK/NACK of thesecondary carrier may be adjusted to the ACK/NACK resource of theprimary carrier for feedback, and the ACK/NACK of the primary carriermay also be adjusted to the ACK/NACK resource of the secondary carrierfor feedback.

For the case that the ACK/NACK of the secondary carrier may be adjustedto the ACK/NACK resource of the primary carrier for feedback, and thecase that the ACK/NACK of the primary carrier may also be adjusted tothe ACK/NACK resource of the secondary carrier for feedback, thespecific adjustment is illustrated in FIG. 6 and described above,therefore not further described here.

In the solutions provided by Embodiment 1 and Embodiment 2, both thePcell and the Scell can transmit the ACK/NACK. Considering the adjacentchannel interference suppression problem, carriers in TDD carrieraggregation with different uplink and downlink configurations shouldbelong to different bands, that is, frequencies of aggregated multiplecarriers are far away from each other. Assuming that two TDD carriers C0and C1 of different uplink and downlink configurations are aggregated,where C0 is in a low band and C1 is in a high band, cell coverage on C0is greater than cell coverage on C1. Therefore, for a UE located at acell edge, the network-side device may configure the uplink ACK/NACK ofthe UE to the low-band carrier C0 with good cell coverage. Particularly,if the low-band carrier is a primary carrier of the UE, the network-sidedevice may configure the uplink ACK/NACK of the UE to the primarycarrier.

Another solution provided by the present invention according to theabove analysis, on the network-side device, includes:

determining, by the network-side device, one of multiple ACK/NACKfeedback modes; and

notifying, by the network-side device, the UE of the ACK/NACK feedbackmode through signaling, so that the UE performs ACK/NACK feedbackaccording to the ACK/NACK feedback mode and preconfigured ACK/NACKtiming relationships.

Based on the above solution, the ACK/NACK feedback mode may be that theACK/NACK may be fed back on a Pcell or an Scell, or, the ACK/NACKfeedback mode may be that the ACK/NACK can only be fed back on acarrier, where the carrier may be a primary carrier or a carrier of alow frequency.

Based on the above solution, preferably, the signaling may be radioresource control (RRC, Radio Resource Control) dedicated signaling,broadcast signaling or layer-1/layer-2 signaling (such as PDCCH).

Based on the above solution, the preconfigured ACK/NACK timingrelationships are timing relationships that are learnt by the UE afterthe UE receives the signaling in the above solution, may be timingrelationships of the conventional system, or timing relationshipsmodified according to the conventional system.

Another solution provided by the present invention, on the UE side,includes:

obtaining signaling that is notified by the network-side device and isused to configure an ACK/NACK feedback mode; and

performing, by the UE, ACK/NACK feedback according to the signaling andpreconfigured ACK/NACK timing relationships.

The ACK/NACK feedback mode and ACK/NACK timing relationship in the abovesolution are described in the corresponding network-side devicesolution, and are not further described here.

The embodiments corresponding to FIG. 16 and FIG. 17 solve the followingtechnical problem: if the ACK/NACK is always fed back on the primarycarrier, in some scenarios, the ACK/NACK may fail to be fed back, forexample, when on a first carrier corresponding to a timing relationship,a subframe of the same time as the subframe carrying the downlink PDSCHis an uplink subframe, the first carrier corresponding to the timingrelationship cannot be used to carry the ACK/NACK corresponding to thePDSCH. Further, if the downlink data, is scheduled in an uplink subframeon the conventional TDD carrier or is scheduled in an uplink subframeused for uplink ACK/NACK feedback on a dynamic subframe TDD carrier (theACK/NACK feedback is decided by the second TDD configuration), theACK/NACK cannot be fed back on the current TDD carrier according to theACK/NACK timing relationship on the current TDD carrier or the ACK/NACKtiming relationship under the second TDD configuration.

With respect to the above problem, the present invention furtherprovides a method for transmitting acknowledgement or negativeacknowledgement indication information. The embodiment of the presentinvention is applicable to a TDD system, an FDD system, and a systemwhere TDD and FDD carriers are aggregated.

This method may be executed by a network-side device, and specificallyincludes:

Step i1. A network-side device configures at least two carriers for aUE, where the carriers include at least one TDD carrier.

Step i2. The network-side device transmits PDCCH information to the UEin a fifth subframe on one of the TDD carriers, where the PDCCHinformation indicates scheduling information of a PDSCH carried in afourth uplink subframe.

The fifth subframe may be an uplink subframe or may also be a downlinksubframe. When the fifth subframe is an uplink subframe, it may be asame uplink subframe as the fourth uplink subframe, and of course, mayalso be an uplink subframe different from the fourth uplink subframe.The fifth subframe may be on the TDD carrier or may also be on othercarriers.

The at least one TDD carrier may use a dynamic subframe configuration,that is, at least one subframe may exist on the TDD carrier, where thesubframe may be dynamically used as an uplink or downlink subframe.Specifically, the uplink and downlink configuration notified by systeminformation is a first TDD configuration, for example, the subframeconfiguration under the first TDD configuration is configuration 0,namely, “DL DL UL UL UL”, while the uplink ACK/NACK feedback timing maybe performed according to the second TDD configuration, where the secondTDD configuration may be configured through a RRC dedicated signaling.Assuming that the subframe configuration under the second configurationis configuration 2, namely, “DL DL UL DL DL”, under the aboveconfiguration, if downlink data of the fourth or fifth subframe isscheduled, the corresponding ACK/NACK may be fed back according to thetiming relationship of the second TDD configuration. The fourth uplinksubframe may be a third subframe under the above configuration, namely,an uplink subframe under the second TDD configuration of the dynamicsubframe TDD carrier.

The fourth uplink subframe is a subframe temporarily used fortransmitting the downlink PDSCH data, and/or, the uplink subframe maycarry the uplink ACK/NACK when not transmitting the downlink PDSCH data.

Step i3. Determine the second carrier where the UE transmits theACK/NACK corresponding to the PDSCH, where the second carrier is acarrier other than the TDD carrier, and specifically may be an FDDcarrier or a TDD carrier.

Because the fourth uplink subframe is an uplink subframe on theconventional TDD carrier (non-dynamic subframe TDD carrier), or anuplink subframe under the second TDD configuration of the dynamicsubframe TDD carrier, if downlink data transmission is scheduled in thefourth uplink subframe, namely, PDSCH transmission, according to theACK/NACK timing relationship on the conventional TDD carrier or theACK/NACK timing relationship on the dynamic subframe TDD carrier,namely, an ACK/NACK timing relationship under the second TDDconfiguration, the corresponding ACK/NACK corresponding to the PDSCHcannot be fed back. Therefore, the ACK/NACK corresponding to the PDSCHneeds to be transmitted on other carriers.

If the number of carriers, except the current TDD carrier, configuredfor the UE is 1, the carrier for the ACK/NACK feedback is a carrierother than the current TDD carrier; if the number of carriers, exceptthe current TDD carrier, configured for the UE is greater than 1,according to the ACK/NACK load and/or feedback delay, among the carriersexcept the current TDD carrier, the second carrier is determined forACK/NACK feedback, and then the information about the second carrier maybe notified to the UE through layer-1 signaling or RRC signaling.

Step i4. Determine a second timing relationship of the ACK/NACK feedbackcorresponding to the PDSCH, and determine, according to the secondtiming relationship, the sixth subframe in which the ACK/NACK is fedback.

The network-side device may determine the second timing relationshipthrough the second carrier, and specifically, may use the timingrelationship between the PDSCH on the second carrier and the ACK/NACK asthe second timing relationship.

The sequence of steps i3 and i4 may be interchanged, that is, the secondtiming relationship may be first determined, and then the second carrierand the sixth subframe for ACK/NACK feedback may be determined accordingto the second timing relationship.

Step i5. In the sixth subframe of the second carrier, determine a secondchannel resource for the UE to feed back the ACK/NACK, and indicate thesecond channel resource to the UE.

Specifically, the ACK/NACK channel resource may be indicated in animplicit manner, for example, the ACK/NACK channel resource mayimplicitly correspond to the identifier of the CCE occupied by thePDCCH. Thereby, the network-side device receives, on an ACK/NACK channelresource corresponding to a CCE that is used by the network-side deviceto schedule the PDCCH, the ACK/NACK transmitted by the UE, where the CCEmay also be an enhanced CCE corresponding to an enhanced PDCCH; and theACK/NACK channel resource may also be indicated explicitly throughsignaling, for example, one or a group of ACK/NACK channel resources isreserved through RRC signaling. If one ACK/NACK channel resource isreserved, the network-side device receives, on the channel resource, theACK/NACK transmitted by the UE. If a group of ACK/NACK channel resourcesis reserved, the network-side device further needs to dynamicallyindicate, through the PDCCH, which resource in the group of ACK/NACKchannel resources is used as a channel resource for the current UE tofeed back the ACK/NACK; and correspondingly, the network-side devicereceives, on the channel resource dynamically indicated, the ACK/NACKtransmitted by the UE. Specifically, the channel resource may beindicated by a bit or scrambling code in the PDCCH.

Step i6. Receive the ACK/NACK that is transmitted by the UE on thesecond channel resource in the sixth subframe of the second carrier.

The corresponding method on the UE side is as follows:

Step j1. A UE determines configured at least two carriers, where thecarriers include at least one TDD carrier.

Step j2. Receive PDCCH information in a fifth subframe on one of the TDDcarriers, where the PDCCH information indicates scheduling informationof a PDSCH carried in a fourth uplink subframe.

The fifth subframe may be an uplink subframe or may also be a downlinksubframe. When the fifth subframe is an uplink subframe, it may be asame uplink subframe as the fourth uplink subframe, and of course, mayalso be an uplink subframe different from the fourth uplink subframe.The fifth subframe may be on the TDD carrier or may also be on othercarriers.

The at least one TDD carrier may use a dynamic subframe configuration,that is, at least one subframe may exist on the TDD carrier, where thesubframe may be dynamically used as an uplink or downlink subframe.Specifically, the uplink and downlink configuration notified by systeminformation is a first TDD configuration, for example, the subframeconfiguration under the first TDD configuration is configuration 0,namely, “DL DL UL UL UL”, while the uplink ACK/NACK feedback timing maybe performed according to the second TDD configuration, where the secondTDD configuration may be configured through a RRC dedicated signaling.Assuming that the subframe configuration under the second configurationis configuration 2, namely, “DL DL UL DL DL”, under the aboveconfiguration, if downlink data of the fourth or fifth subframe isscheduled, the corresponding ACK/NACK may be fed back according to thetiming relationship of the second TDD configuration.

The fourth uplink subframe may be a third subframe under the aboveconfiguration, namely, an uplink subframe under the second TDDconfiguration of the dynamic subframe TDD carrier.

The fourth uplink subframe is a subframe temporarily used fortransmitting the downlink PDSCH data, and/or, the uplink subframe maycarry the uplink ACK/NACK when not transmitting the downlink PDSCH data.

Step j3. Determine the second carrier where the ACK/NACK correspondingto the PDSCH is transmitted, where the second carrier is a carrier otherthan the TDD carrier, and specifically may be an FDD carrier or a TDDcarrier.

Because the fourth uplink subframe is an uplink subframe on theconventional TDD carrier (non-dynamic subframe TDD carrier), or anuplink subframe under the second TDD configuration of the dynamicsubframe TDD carrier, if downlink data transmission is scheduled in thefourth uplink subframe, namely, PDSCH transmission, according to theACK/NACK timing relationship on the conventional TDD carrier or theACK/NACK timing relationship on the dynamic subframe TDD carrier,namely, an ACK/NACK timing relationship under the second TDDconfiguration, the corresponding ACK/NACK corresponding to the PDSCHcannot be fed back. Therefore, the ACK/NACK corresponding to the PDSCHneeds to be transmitted on other carriers.

If the number of carriers, except the current TDD carrier, configuredfor the UE is 1, the carrier for the ACK/NACK feedback is a carrierother than the current TDD carrier; if the number of carriers, exceptthe current TDD carrier, configured for the UE is greater than 1, the UEmay determine, among the carriers except the current TDD carrier byreceiving layer-1 signaling or RRC signaling transmitted by thenetwork-side device, that the second carrier is used for ACK/NACKfeedback.

Step j4. Determine a second timing relationship of the ACK/NACK feedbackcorresponding to the PDSCH, and determine, according to the secondtiming relationship, the sixth subframe in which the ACK/NACK is fedback.

The UE may determine the second timing relationship through the secondcarrier, and specifically, may use the timing relationship between thePDSCH on the second carrier and the ACK/NACK as the second timingrelationship.

The sequence of steps j3 and j4 may be interchanged, that is, the secondtiming relationship may be first determined, and then the second carrierand the sixth subframe for ACK/NACK feedback may be determined accordingto the second timing relationship. Specifically, the UE may determinethe second timing relationship by receiving the layer-1 signaling or RRCsignaling transmitted by the network-side device.

Step j5. In the sixth subframe of the second carrier, determine a secondchannel resource used for the UE to feed back the ACK/NACK.

Specifically, the ACK/NACK channel resource may be indicated in animplicit manner, for example, the ACK/NACK channel resource mayimplicitly correspond to the identifier of the CCE occupied by thePDCCH. Thereby, the UE transmits the ACK/NACK, on an ACK/NACK channelresource corresponding to a CCE that is used by the network-side deviceto schedule the PDCCH, where the CCE may also be an enhanced CCEcorresponding to an enhanced PDCCH; and the ACK/NACK channel resourcemay also be indicated explicitly through signaling, for example, one ora group of ACK/NACK channel resources is reserved through RRC signaling.If one ACK/NACK channel resource is reserved, the UE transmits, on thechannel resource, the ACK/NACK. If a group of ACK/NACK channel resourcesis reserved, the UE further needs to dynamically determine, by receivingthe PDCCH, which one resource in the group of ACK/NACK channel resourcesis used as a channel resource for the current ACK/NACK feedback; andcorrespondingly, the UE transmits, on the channel resource dynamicallyindicated, the ACK/NACK. Specifically, the channel resource may bedetermined by receiving a bit or scrambling code in the PDCCH.

Step j6. The UE transmits the ACK/NACK on the second channel resource inthe sixth subframe of the second carrier.

For example:

It is assumed that the network-side device configures two carriers forthe UE, where carrier 1 is an FDD carrier, and carrier 2 is a TDDcarrier, where the TDD carrier is a conventional TDD carrier, namely,not using the dynamic subframe configuration; it is assumed that theuplink and downlink configuration of the TDD carrier is configuration 2,that is, configurations of 10 subframes of a radio frame are DSUDDDSUDD(DL DL UL DL DL DL DL UL DL DL), where S indicates a special subframe,and the subframe may transmit downlink data PDSCH but cannot transmituplink PUSCH data and therefore may be used as a downlink subframe. Thenetwork-side device may schedule PDSCHs in the eight downlink subframesof the TDD carrier. The ACKs/NACKs corresponding to the PDSCHs may betransmitted on the uplink subframe of the TDD carrier, and may also betransmitted on the uplink subframe of the FDD carrier. In addition, thenetwork-side device may schedule downlink PDSCH data in the uplinksubframe of the TDD carrier. Correspondingly, if the uplink subframe ofthe TDD carrier is not used to feed back the uplink ACK/NACK, the UEneeds to monitor PDCCH information in the uplink subframe. If thenetwork-side device schedules downlink PDSCH data in the uplinksubframe, because the uplink subframe of the current TDD carrier hasonly ACK/NACK feedback timing of the downlink subframe on the carrier,if the uplink subframe is used for downlink transmission, the currentTDD carrier has no ACK/NACK timing of the downlink transmission.Therefore, the UE needs to determine the carrier carrying the ACK/NACKcorresponding to the PDSCH, which may be specifically determined by theUE, or may also be allocated by the network-side device. The carrierthat feeds back the ACK/NACK is a carrier other than the current TDDcarrier.

Specifically, in the case that the UE determines the carrier, if the UEis configured with two carries, the UE may feed back the ACK/NACK on theother carrier than the carrier carrying the current PDSCH, where theother carrier may be an FDD carrier or a TDD carrier; if the othercarrier is a TDD carrier, the subframe of the same time as the fourthuplink subframe of the current TDD carrier is a downlink subframe. Onlythis may ensure that uplink ACK/NACK timing of the downlink datatransmission in the fourth uplink subframe exists on the other TDDcarrier. If the other carrier is an FDD carrier, it may be definitelyensured that the uplink ACK/NACK timing of the downlink datatransmission in the fourth uplink subframe exists, for example, theACK/NACK may be fed back in the subframe of the FDD carrier after foursubframes from the fourth uplink subframe.

In the case that the network-side device configures the carrier carryingthe ACK/NACK corresponding to the PDSCH, assuming that the UE isconfigured with more than two carriers, the UE may feed back theACK/NACK on other carriers according to the indication of thenetwork-side device. The determination may be specifically performedaccording to layer-1 signaling or RRC signaling or the combination oflayer-1 signaling and RRC signaling.

The timing relationship of the ACK/NACK feedback may be just the timingrelationship on a selected carrier, namely, a timing relationship of theACK/NACK feedback corresponding to the downlink subframe of the sametime as the fourth uplink subframe on the selected carrier. The timingrelationship may also be determined before the carrier that feeds backthe ACK/NACK is determined, and specifically, may be determined byselecting a timing relationship that has the shortest delay, and thenthe carrier of the timing relationship is selected as the carrier forfeeding back the ACK/NACK. That is, the sequence of determining thesubframe for feeding back the ACK/NACK and determining the carriercarrying the ACK/NACK is not limited.

Then the UE needs to determine a channel resource used for ACK/NACKfeedback, which may be specifically configured by the network-sidedevice through layer-1 signaling or RRC signaling or the combination ofthe layer-1 signaling and RRC signaling, for example, allocatedexplicitly through a bit (such as an ARI) in the PDCCH and othermanners, or allocated implicitly through a CCE identifier and othermanners, or a group of ACK/NACK channel resources may be configuredthrough RRC signaling, and then a bit in the PDCCH is used to determineone of the ACK/NACK channel resources.

In the case that the current TDD carrier uses a dynamic subframeconfiguration, assuming that the first TDD configuration of the TDDcarrier notified by system information is configuration 0, that is, thesubframe configuration is “DL DL UL UL UL DL DL UL UL UL”, and that thetiming relationship between the PDSCH of the carrier and the ACK/NACK isoperated according to the second TDD configuration, the second TDDconfiguration is configured through RRC dedicated signaling.Specifically, the fourth and fifth subframes are uplink subframesaccording to the first TDD configuration, but may be used for downlinkdata transmission, and their corresponding uplink ACK/NACK feedback maybe performed according to the second TDD configuration, that is, thefeedback may be performed on the third or eighth subframe, that is, thetwo subframes are fixed uplink subframes, while the fourth, fifth,ninth, and tenth subframes may be understood as dynamic subframes.

In the present invention, it is assumed that a TDD carrier of a dynamicsubframe and another carrier are configured, where the other carrier maybe an FDD carrier or a TDD carrier. For the fixed uplink subframe of thecurrent TDD carrier, for example, when the subframes 3 and 8 are usedfor downlink data transmission, their corresponding ACK/NACK feedbackcannot be performed according to the timing relationship between thefirst TDD configuration and the second TDD configuration. Therefore, theACK/NACK may be fed back on another FDD or TDD carrier, where a timingrelationship on another carrier may be used as the timing relationship.The configuration of the second channel resource is consistent with theconfiguration in the above embodiment, and is not further describedhere.

The present invention further provides a network-side device. Thenetwork-side device may be a device in a TDD system, an FDD system, or asystem where TDD and FDD carriers are aggregated.

Specifically, the network-side device may include the following:

A transmitting unit which is configured to transmit PDCCH information toa UE in a fifth subframe on a TDD carrier, where the PDCCH informationindicates scheduling information of a PDSCH carried in a fourth uplinksubframe; and indicate, to the UE, a second channel resource that isdetermined by a processing unit in a sixth subframe of a second carrier.

The relationship between the fifth subframe and the fourth uplinksubframe, and the PDCCH information, are specifically described in thecorresponding method embodiment above, and are not further describedhere.

The fourth uplink subframe may be specifically an uplink subframe underthe second TDD configuration of the dynamic subframe TDD carrier, wherethe second TDD configuration is a TDD configuration that decides thetiming relationship between the PDSCH on the TDD carrier and anACK/NACK, and may be configured through RRC dedicated signaling.

The network-side device may also include the processing unit, which isconfigured to configure at least two carriers for the UE, where thecarriers include at least one TDD carrier; determine a second carrierfor the UE to transmit the ACK/NACK corresponding to the PDSCH, wherethe second carrier is a carrier other than the TDD carrier, and may bespecifically an FDD carrier or a TDD carrier; determine a second timingrelationship of the ACK/NACK feedback corresponding to the PDSCH, anddetermine, according to the second timing relationship, a sixth subframefor feeding back the ACK/NACK; and determine a second channel resourceon the sixth subframe of the second carrier for the UE to feed back theACK/NACK.

Methods for determining the second carrier, second timing relationship,sixth subframe, and second channel resource are described in thecorresponding method embodiment above, and are not further describedhere.

The network-side device may also include a receiving unit, which isconfigured to receive the ACK/NACK transmitted by the UE on the secondchannel resource in the sixth subframe of the second carrier.

The processing unit may specifically include: a configuring unit, acarrier determining unit, a timing relationship and subframe determiningunit, and a channel resource determining unit.

The configuring unit is configured to configure at least two carriers,where the carriers include at least one TDD carrier.

The carrier determining unit is configured to determine a second carrierused for the UE to transmit the ACK/NACK corresponding to the PDSCH.

The timing relationship and subframe determining unit is configured todetermine the second timing relationship of the ACK/NACK feedbackcorresponding to the PDSCH, and determine, according to the secondtiming relationship, a sixth subframe for feeding back the ACK/NACK.

The channel resource determining unit is configured to: in the sixthsubframe determined by the timing relationship and subframe determiningunit, and on the second carrier determined by the carrier determiningunit, determine a second channel resource used for the UE to feed backthe ACK/NACK.

The processing method in the processing unit is described in thecorresponding method embodiment above, and is not further describedhere.

The present invention further provides a user equipment. The userequipment may be a device in a TDD system, an FDD system, or a systemwhere TDD and FDD carriers are aggregated.

Specifically, the user equipment may include the following:

A receiving unit, which is configured to receive PDCCH information in afifth subframe on one TDD carrier, where the PDCCH information indicatesscheduling information of a PDSCH carried in a fourth uplink subframe.

The relationship between the fifth subframe and the fourth uplinksubframe, and the PDCCH information, are specifically described in thecorresponding method embodiment above, and are not further describedhere.

The fourth uplink subframe may be specifically an uplink subframe underthe second TDD configuration of the dynamic subframe TDD carrier, wherethe second TDD configuration is a TDD configuration that decides thetiming relationship between the PDSCH on the TDD carrier and anACK/NACK, and may be configured through RRC dedicated signaling.

The user equipment may also include a processing unit, which isconfigured for the UE to determine at least two carriers configured bythe network-side device, where the carriers include at least one TDDcarrier; determine a second carrier for transmitting the ACK/NACKcorresponding to the PDSCH, where the second carrier is a carrier otherthan the TDD carrier, and may be specifically an FDD carrier or a TDDcarrier; determine a second timing relationship of the ACK/NACK feedbackcorresponding to the PDSCH, and determine, according to the secondtiming relationship, a sixth subframe for feeding back the ACK/NACK; anddetermine a second channel resource on the sixth subframe of the secondcarrier for the UE to feed back the ACK/NACK.

Methods for determining the second carrier, second timing relationship,sixth subframe, and second channel resource are described in thecorresponding method embodiment above, and are not further describedhere.

The user equipment may also include a transmitting unit, which isconfigured for the UE to transmit the ACK/NACK on the second channelresource in the sixth subframe of the second carrier which is determinedby the processing unit.

The processing unit may specifically include: a configured carrierdetermining unit, an ACK/NACK feedback carrier determining unit, atiming relationship and subframe determining unit, and a channelresource determining unit.

The configured carrier determining unit is configured for the UE todetermine at least two carriers configured by the network-side device,where the carriers include at least one TDD carrier.

The ACK/NACK feedback carrier determining unit is configured todetermine a second carrier for transmitting the ACK/NACK correspondingto the PDSCH, where the second carrier is a carrier other than the TDDcarrier, and may be specifically an FDD carrier or a TDD carrier.

The timing relationship and subframe determining unit is configured todetermine the second timing relationship of the ACK/NACK feedbackcorresponding to the PDSCH, and determine, according to the secondtiming relationship, a sixth subframe for feeding back the ACK/NACK.

The channel resource determining unit is configured to: in the sixthsubframe determined by the timing relationship and subframe determiningunit, and on the second carrier determined by the ACK/NACK feedbackcarrier determining unit, determine a second channel resource used forthe UE to feed back the ACK/NACK.

The processing method in the processing unit is described in thecorresponding method embodiment above, and is not further describedhere.

Embodiment 3

In the prior art, when a PUCCH format 1b combined with an ACK/NACKfeedback mode based on channel selection is used, if the number ofACK/NACK original bits or original bits after codeword binding isgreater than 4, the number of ACK/NACK bits is reduced by binding theACK/NACK time domain portions so that the number of ACK/NACK bits is notgreater than 4. As shown in FIG. 7, it is assumed that insingle-codeword transmission, the total number of ACK/NACK bits fed backby subframe 2 and subframe 7 is 6; using subframe 2 as an example, theACKs/NACKs fed back by uplink subframe 2 in the Pcell, corresponding todownlink subframes 5 and 6, may be bound as 2 bits, and the ACKs/NACKsfed back by uplink subframe 2 in the Scell, corresponding to downlinksubframes 4, 5, 6, and 8, may be bound as 2 bits, that is, 2 bits percarrier, and 4 ACK/NACK bits in total in subframes 2. Therefore, thePUCCH format 1b combined with an ACK/NACK feedback mode based on channelselection may be used. 2 bits bound with each carrier may be obtainedaccording to Table 1, namely, the total number of ACKs after eachcarrier is bound. The specific mapping relationship is: the four statesindicated by the 2 bits are respectively 00 (indicating that among boundACKs/NACKs, at least one NACK exists), (indicating that there is no NACKand that the number of ACKs is 1 or 4), 01 (indicating that there is noNACK and that the number of ACKs is 2), and 11 (indicating that there isno NACK and that the number of ACKs is 3). Another state is that if theUE finds that a PDCCH is undetected or that a PDCCH is not received, theUE does not transmit any ACK/NACK.

The UE determines, according to a 2-bit DAI field in the PDCCH scheduledin bound several downlink subframes, whether a PDCCH is undetected,where the DAI count is accumulative based on each subframe. Usingdownlink subframes 4, 5, 6, and 8 of the Scell as examples, if thenetwork-side device schedules the four downlink subframes, thecorresponding DAI values in four PDCCHs are 1, 2, 3, and 4; if the UEreceives only the PDCCHs whose DAIs are 1, 3, and 4, the UE determinesthat an eNB (base station) schedules downlink subframe 5 but the UEitself leaves the PDCCH undetected; therefore, the UE does not transmitany ACK/NACK. In addition, Table 1 shows only a mapping relationship,not excluding other similar mapping relationships.

TABLE 1 Total Number of Bound ACKs ACK/NACK State 0 (at least one NACK)0, 0 The UE finds that a PDCCH is undetected Not transmitted, not orthat a PDCCH is not received transmitted 1 1, 0 2 0, 1 3 1, 1 4 1, 0 50, 1 6 1, 1 7 1, 0 8 0, 1 9 1, 1

As seen from the state “1, 0” fed back by the UE in Table 1, the stateindicates that there is no NACK and that the number of ACKs is 1 or 4,and therefore an error occurs. Specifically, if the eNB schedulessubframes 4, 5, 6, and 8 to the UE, but the UE receives only the PDCCHof subframe 4, where the DAI value is 1, and the UE obtains a PDCCH fromthe data scheduling. In this case, the UE does not find that thesubsequent 3 PDCCHs are undetected, and therefore no NACK is nottransmitted; therefore, the UE binds the ACK/NACK of the carrier to thestate “1, 0” and feeds back the state to the eNB, indicating that thenumber of ACKs is 1. However, the eNB schedules four PDCCHs, andconsiders, when obtaining the “1, 0” fed back by the UE, that the numberof ACKs fed back by the UE is 4. Therefore, the subsequent three datapackets are lost. The error occurs because the state “1, 0” fed back bythe UE is an overlapped state, namely, the state has two meanings.

To solve the problem of an ACK/NACK feedback information error caused bythe conventional DAI counting mode, the DAI counting mode may bechanged. Using the above case as an example, the DAI value may be notset to be greater than or equal to 4, and the present invention providesthe following solution:

This embodiment provides a method for transmitting acknowledgement ornegative acknowledgement indication information in a TDD system.

As shown in FIG. 8, this method may be executed by a network-sidedevice, and specifically includes:

S51. Configure at least two carriers for a UE, where subframe n of atleast two carriers among the configured carriers is an uplink subframeand needs to feed back an ACK/NACK.

S52. Divide downlink subframes corresponding to the ACK/NACK thatsubframe n needs to feed back, into at least two groups, where thenumber of downlink subframes in each group does not exceed 2^(N)−1,where N indicates the number of bits of a DAI, where downlink subframesin at least one group belong to different carriers.

S53. Set the DAI value in the PDCCH information corresponding to eachdownlink subframe in each group to 1 to 2^(N)−1 in turn.

S54. Transmit the PDCCH information corresponding to the downlinksubframes in each group to the UE.

Specifically, if there are two carriers and subframes are divided intotwo groups, the dividing downlink subframes corresponding to theACK/NACK that subframe n needs to feed back, into at least two groups,may include:

grouping downlink subframes whose transmission time is within the first2^(N)−1 subframes on the first carrier among the downlink subframescorresponding to the ACK/NACK, into a first group, where the 2^(N)−1downlink subframes are called a first group of subframes; and

grouping other downlink subframes than the first group of subframes onthe first carrier among the downlink subframes corresponding to theACK/NACK, and downlink subframes on the second carrier among thedownlink subframes corresponding to the ACK/NACK, into a second group,where the number of downlink subframes in the second group also does notexceed 2^(N)−1.

The case of two carriers is described above; for three or more carriers,and/or three or more groups, the processing principle is similar, andtherefore is not further described here.

Specifically, the setting the DAI value in the PDCCH informationcorresponding to each downlink subframe in each group to 1 to 2^(N)−1 inturn may include:

in each of the groups, setting the DAI values from 1 to 2^(N)−1 in turnaccording to the transmission time sequence of the PDCCH information,where the DAI values are set again according to the carrier sequence forat least two downlink subframes of the same transmission time. Ofcourse, the setting of the DAI value may also use other manners, forexample, use the setting sequence learnt by both the network-side deviceand the UE.

As shown in FIG. 9, this method may be executed by a user equipment, andspecifically includes:

S61. Receive at least two carriers configured by a network-side device,where subframe n of at least two carriers among the configured carriersis an uplink subframe and needs to feed back an ACK/NACK.

S62. Divide downlink subframes corresponding to the ACK/NACK thatsubframe n needs to feed back, into at least two groups, where thenumber of downlink subframes in each group does not exceed 2^(N)−1,where N indicates the number of bits of a DAI, where downlink subframesin at least one group belong to different carriers.

S63. Receive PDCCH information transmitted by the network-side device ineach downlink subframe in each group.

S64. For each group, generate an N-bit ACK/NACK according to the DAIvalue in each piece of PDCCH information in the group and the ACK/NACKcorresponding to the PDSCH indicated by the PDCCH information.

S65. Transmit the generated ACK/NACK corresponding to each group to thenetwork-side device.

According to the method provided by this embodiment, when the number Nof bits of the DAI is 2, the state indication of the DAI when some ofthe ACKs/NACKs are bound is shown in Table 2. As seen from Table 2,because the DAI counting manner is changed, the ACK/NACK feedbackinformation (namely, the ACK/NACK state) has no overlapped state.

TABLE 2 Total Number of Bound ACKs ACK/NACK State 0 (at least one NACK)0, 0 The UE finds that a PDCCH is undetected Not transmitted, not orthat a PDCCH is not received transmitted 1 1, 0 2 0, 1 3 1, 1

The following uses subframe 2 in FIG. 7 as an example to describe thesolution of this embodiment in combination with Table 2.

First, two carriers Pcell and Scell are configured for the UE, andsubframe 2 is an uplink subframe on both the two carriers and needs tofeed back ACKs/NACKs; 6 downlink subframes of two carriers correspondingto the ACKs/NACKs that uplink subframe 2 needs to feed back are dividedinto two groups, where the number of downlink subframes included in eachgroup is 3; the first group is downlink subframes 4, 5, and 6 of theScell, and the second group is downlink subframes 5 and 6 of the Pcelland downlink subframe 8 of the Scell, and the second group crossesdifferent carriers. For downlink subframes 4, 5, and 6 of the firstgroup, the DAI counts are 1, 2, and 3, respectively. For the downlinksubframes 5, 6, and 8 of the second group, the DAI counts are 1, 2, and3, respectively. Therefore, the case that the DAI is 4 may not occur,that is, the UE may not feed back that the number of ACKs is 4. Thereby,an error caused by the overlapped state is avoided.

This embodiment avoids the ACK/NACK feedback information error bychanging the DAI counting manner to avoid overlapping of the ACK/NACKfeedback information.

Embodiment 4

As shown in FIG. 10, this embodiment provides a network-side device. Thenetwork-side device includes:

a configuring unit 101, configured to configure at least two carriersfor a user equipment UE, where the carriers include one primary carrierand at least one secondary carrier;

a processing unit 102, configured to generate physical downlink controlchannel PDCCH information for the UE, where the PDCCH informationindicates scheduling information of a physical downlink shared channelPDSCH carried in a downlink subframe; the PDCCH information indicates anacknowledgement ACK or negative acknowledgement NACK channel resourcecorresponding to the PDSCH, where the ACK/NACK channel resource iscarried in a first uplink subframe on the secondary carrier configuredby the configuring unit 101, where the first uplink subframe isdetermined according to a timing relationship between the PDSCH and theACK/NACK corresponding to the PDSCH, and a subframe of the same time asthe first uplink subframe is a downlink subframe on the primary carrierconfigured by the configuring unit 101;

a transmitting unit 103, configured to transmit the PDCCH informationgenerated by the processing unit 102 to the UE in a downlink subframe;and

a receiving unit 104, configured to receive, in the first uplinksubframe of the secondary carrier where the ACK/NACK channel resourceindicated by the PDCCH information transmitted by the transmitting unit103 is located, the ACK/NACK fed back by the UE.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one secondary carrier, the ACK/NACK channel resourceindicated by the PDCCH information generated by the processing unit 102is carried in the first uplink subframe of the first secondary carrier;

and/or,

if there are two or more first secondary carriers, the ACK/NACK channelresource indicated by the PDCCH information generated by the processingunit 102 is carried in the first uplink subframe of a secondary carrieramong the first secondary carriers,

where the one secondary carrier among the first secondary carriers isone of the following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

If there are two or more first secondary carriers, and the ACK/NACKchannel resource indicated by the PDCCH information generated by theprocessing unit 102 is carried in the first uplink subframe of asecondary carrier of the highest priority among the first secondarycarriers,

the processing unit 102 is further configured to:

determine priorities of secondary carriers among the first secondarycarriers, including: according to the load of the ACK/NACK correspondingto the first uplink subframe on each secondary carrier where the firstuplink subframe is an uplink subframe, or the frequency of eachsecondary carrier, or the index configuration of each secondary carrier,so that the ACK/NACK channel resource indicated by the PDCCH informationgenerated by the processing unit 102 is carried in the first uplinksubframe of the secondary carrier of the highest priority among thefirst secondary carriers;

or, the processing unit 102 is further configured to:

determine priorities for secondary carriers configured for the UE, wherethe determining specifically includes: for each time, determiningpriorities for all secondary carriers where a subframe corresponding tothe time is an uplink subframe; and

determine priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink subframe, so that theACK/NACK channel resource indicated by the PDCCH information generatedby the processing unit 102 is carried in the first uplink subframe ofthe secondary carrier of the highest priority among the first secondarycarriers.

The transmitting unit 103 is further configured to: after determiningthat the ACK/NACK channel resource corresponding to the PDSCH is locatedon the secondary carrier, transmit information about the determinedsecondary carrier to the UE through PDCCH information.

On the network-side device, only one secondary carrier is scheduled forthe UE and no primary carrier is scheduled, where the secondary carrieris a second secondary carrier, and

the ACK/NACK channel resource indicated by the PDCCH informationgenerated by the processing unit 102 is carried in the first uplinksubframe of the second secondary carrier.

The identifier of the control channel element CCE occupied by the PDCCHcorresponds to the ACK/NACK channel resource;

the indicating, by the PDCCH information generated by the processingunit 102, scheduling information of a physical downlink shared channelPDSCH that is carried by the downlink subframe, includes:

indicating the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

The network-side device further includes:

a reserving unit, configured to reserve, through radio resource controlRRC dedicated signaling, an ACK/NACK resource set for the UE in asubframe used for ACK/NACK feedback, where at least one ACK/NACK channelresource included in the ACK/NACK resource set is located on one ormultiple secondary carriers, and each ACK/NACK channel resource in theACK/NACK resource set is carried on a unique secondary carrier;

the indicating, by the PDCCH information generated by the processingunit 102, the ACK/NACK channel resource corresponding to the PDSCH,includes:

using the transmit power control TPC or downlink assignment index DAI inthe PDCCH information transmitted to the UE as an ACK/NACK channelresource indicator ARI, where the ARI is used to indicate an ACK/NACKchannel resource that is included in the ACK/NACK resource set and usedfor the UE to feed back the ACK/NACK, and the carrier carrying theACK/NACK channel resource is a carrier used for the UE to feed back theACK/NACK.

Using the TPC in the PDCCH information generated by the processing unit102 as an ARI, includes:

selecting one of the secondary carriers where the first uplink subframecorresponds to an uplink subframe, as a third secondary carrier;

scheduling a TPC command word in the PDCCH information corresponding tothe PDSCH carried on the third carrier as a TPC command word; and

scheduling a TPC command word in the PDCCH information corresponding toother PDSCHs as an ARI, where the other PDSCHs are carried on one ormultiple secondary carriers among other secondary carriers than thethird secondary carrier, and the ARI values are the same when the otherPDSCHs are carried on multiple secondary carriers.

The processing unit 102 is further configured to:

determine priorities for secondary carriers configured for the UE, wherethe determining includes: for each time, determining priorities for allsecondary carriers where a subframe corresponding to the time is anuplink subframe; and

the third secondary carrier is a secondary carrier of the highestpriority among the secondary carriers where the first uplink subframecorresponds to an uplink subframe.

The determining, by the processing unit 102, priorities for allsecondary carriers where a subframe corresponding to the time is anuplink subframe, includes:

according to the load of the ACK/NACK on each secondary carrier wherethe subframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier.

In brief, the network-side device provided by this embodiment mayinclude:

a configuring unit, configured to configure at least two carriers for auser equipment UE, where the carriers include one primary carrier and atleast one secondary carrier;

a processing unit, configured to generate physical downlink controlchannel PDCCH information for the UE, where the PDCCH informationindicates scheduling information of a physical downlink shared channelPDSCH carried in a downlink subframe; the PDCCH information indicates anacknowledgement ACK or negative acknowledgement NACK channel resourcecorresponding to the PDSCH, where the ACK/NACK channel resource iscarried in a first uplink subframe on the secondary carrier configuredby the configuring unit, where the first uplink subframe is determinedaccording to a timing relationship between the PDSCH and the ACK/NACKcorresponding to the PDSCH, and a subframe of the same time as the firstuplink subframe is a downlink subframe on the primary carrier configuredby the configuring unit;

a transmitting unit, configured to transmit the PDCCH informationgenerated by the processing unit to the UE in a downlink subframe; and

a receiving unit, configured to receive, in the first uplink subframe ofthe secondary carrier where the ACK/NACK channel resource indicated bythe PDCCH information transmitted by the transmitting unit is located,the ACK/NACK fed back by the UE.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one first secondary carrier, the ACK/NACK channel resourceindicated by the PDCCH information generated by the processing unit iscarried in the first uplink subframe of the first secondary carrier;

and/or,

if there are two or more first secondary carriers, the ACK/NACK channelresource indicated by the PDCCH information generated by the processingunit is carried in the first uplink subframe of one secondary carrieramong the first secondary carriers,

where the one secondary carrier among the first secondary carriers isone of the following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

Correspondingly, if there are two or more first secondary carriers, andthe ACK/NACK channel resource indicated by the PDCCH informationgenerated by the processing unit is carried in the first uplink subframeof the secondary carrier of the highest priority among the firstsecondary carriers,

the processing unit is further configured to:

determine priorities of secondary carriers among the first secondarycarriers, including: according to the load of the ACK/NACK correspondingto the first uplink subframe on each secondary carrier where the firstuplink subframe is an uplink subframe, or the frequency of eachsecondary carrier, or the index configuration of each secondary carrier,so that the ACK/NACK channel resource indicated by the PDCCH informationgenerated by the processing unit is carried in the first uplink subframeof the secondary carrier of the highest priority among the firstsecondary carriers;

or, configured to:

determine priorities for secondary carriers configured for the UE, wherethe determining includes: for each time, determining priorities for allsecondary carriers where a subframe corresponding to the time is anuplink subframe; and

determine priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink subframe, so that theACK/NACK channel resource indicated by the PDCCH information generatedby the processing unit is carried in the first uplink subframe of thesecondary carrier of the highest priority among the first secondarycarriers.

The transmitting unit is further configured to: after determining thatthe ACK/NACK channel resource corresponding to the PDSCH is located onthe secondary carrier, transmit information about the determinedsecondary carrier to the UE through the PDCCH information.

On the network-side device, only one secondary carrier is scheduled forthe UE and no primary carrier is scheduled, where the secondary carrieris a second secondary carrier, and

the ACK/NACK channel resource indicated by the PDCCH informationgenerated by the processing unit is carried in the first uplink subframeof the second secondary carrier.

The identifier of the control channel element CCE occupied by the PDCCHcorresponds to the ACK/NACK channel resource;

the indicating, by the PDCCH information generated by the processingunit, scheduling information of a physical downlink shared channel PDSCHthat is carried by the downlink subframe, includes:

indicating the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

The network-side device further includes:

a reserving unit, configured to reserve, through radio resource controlRRC dedicated signaling, an ACK/NACK resource set for the UE in asubframe used for ACK/NACK feedback, where at least one ACK/NACK channelresource included in the ACK/NACK resource set is located on one ormultiple secondary carriers, and each ACK/NACK channel resource in theACK/NACK resource set is carried on a unique secondary carrier;

the indicating, by the PDCCH information generated by the processingunit, the ACK/NACK channel resource corresponding to the PDSCH,includes:

using the transmit power control TPC or downlink assignment index DAI inthe PDCCH information transmitted to the UE as an ACK/NACK channelresource indicator ARI, where the ARI is used to indicate an ACK/NACKchannel resource that is included in the ACK/NACK resource set and usedfor the UE to feed back the ACK/NACK, and the carrier carrying theACK/NACK channel resource is a carrier used for the UE to feed back theACK/NACK.

Correspondingly, the using the TPC in the PDCCH information generated bythe processing unit as an ARI, includes:

selecting one of the secondary carriers where the first uplink subframecorresponds to an uplink subframe, as a third secondary carrier;

scheduling a TPC command word in the PDCCH information corresponding tothe PDSCH carried on the third carrier as a TPC command word; and

scheduling a TPC command word in the PDCCH information corresponding toother PDSCHs as an ARI, where the other PDSCHs are carried on one ormultiple secondary carriers among other secondary carriers than thethird secondary carrier, and the ARI values are the same when the otherPDSCHs are carried on multiple secondary carriers.

Correspondingly, the processing unit is further configured to:

determine priorities for secondary carriers configured for the UE, wherethe determining includes: for each time, determining priorities for allsecondary carriers where a subframe corresponding to the time is anuplink subframe;

the third secondary carrier is a secondary carrier of the highestpriority among the secondary carriers where the first uplink subframecorresponds to an uplink subframe.

Correspondingly, the determining, by the processing unit, priorities forall secondary carriers where a subframe corresponding to the time is anuplink subframe, includes:

according to the load of the ACK/NACK on each secondary carrier wherethe subframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier.

The network-side device provided by this embodiment indicates, throughPDCCH information, that the ACK/NACK channel resource corresponding tothe PDSCH is carried in the first uplink subframe on the secondarycarrier and that a subframe of the same time as the first uplinksubframe is a downlink subframe on the primary carrier, so that the UEfeeds back, on the ACK/NACK channel resource in the first uplinksubframe of the determined secondary carrier, the ACK/NACK correspondingto the PDSCH, so that the ACK/NACK can also be fed back when carriers ofdifferent uplink and downlink subframe configurations are aggregated.

Embodiment 5

As shown in FIG. 11, this embodiment provides a user equipment UE, wherethe UE includes:

a receiving unit 201, configured to receive physical downlink controlchannel PDCCH information transmitted by a network-side device to the UEin a downlink subframe;

a determining unit 202, configured to determine, according to schedulinginformation carried in the PDCCH information received by the receivingunit 201, a physical downlink shared channel PDSCH scheduled by thePDCCH information; determine, according to the PDCCH information, anacknowledgement ACK or negative acknowledgement NACK channel resourcecorresponding to the PDSCH; determine, according to a timingrelationships between the PDSCH and the ACK/NACK corresponding to thePDSCH, a first uplink subframe used for feeding back the ACK/NACK, wherea subframe of the same time as the first uplink subframe is a downlinksubframe on a primary carrier; and determine a secondary carriercarrying the ACK/NACK channel resource; and

a transmitting unit 203, configured to feed back, on the ACK/NACKchannel resource determined by the determining unit 202, the ACK/NACKcorresponding to the PDSCH, where the ACK/NACK channel resource islocated in a first uplink subframe of the determined secondary carrier.

The receiving unit 201 is further configured to receive radio resourcecontrol RRC dedicated signaling transmitted by the network-side device;

the determining unit 202 is further configured to obtain, according tothe RRC dedicated signaling received by the receiving unit 201, anACK/NACK resource set that is reserved by the network-side device forthe UE in a subframe used for ACK/NACK feedback, where at least oneACK/NACK channel resource included in the ACK/NACK resource set islocated on one or multiple secondary carriers, and each ACK/NACK channelresource in the ACK/NACK resource set is carried on a unique secondarycarrier; and

the determining, by the determining unit 202 according to the PDCCHinformation, an ACK/NACK channel resource corresponding to the PDSCH,includes:

obtaining, by the determining unit 202, the transmit power control TPCor downlink assignment index DAI that is included in the PDCCHinformation transmitted by the network-side device and is used as anACK/NACK channel resource indicator ARI, and determining, according tothe ARI, an ACK/NACK channel resource that is included in the ACK/NACKresource set and is used for the UE to feed back the ACK/NACK, where thecarrier carrying the ACK/NACK channel resource is a carrier used for theUE to feed back the ACK/NACK.

The obtaining, by the determining unit 202, the TPC or DAI that is usedas the ACK/NACK channel resource indicator ARI, includes:

selecting one of the secondary carriers where the first uplink subframecorresponds to an uplink subframe, as a third secondary carrier;

using a TPC command word in the PDCCH information corresponding to thePDSCH carried on the third carrier as a TPC command word; and

using a TPC command word in the PDCCH information corresponding to otherPDSCHs as an ARI, where the other PDSCHs are carried on one or multiplesecondary carriers among other secondary carriers than the thirdsecondary carrier, and the ARI values are the same when the other PDSCHsare carried on multiple secondary carriers.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one first secondary carrier, the determining, by thedetermining unit 202, the secondary carrier carrying the ACK/NACKchannel resource, includes:

determining the secondary carrier carrying the ACK/NACK channel resourceas a first secondary carrier;

and/or,

if there are two or more first secondary carriers, the determining asecondary carrier carrying the ACK/NACK channel resource includes:determining the secondary carrier carrying the ACK/NACK channel resourceas one secondary carrier among the first secondary carriers;

the one secondary carrier among the first secondary carriers is one ofthe following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

If there are two or more first secondary carriers, and the secondarycarrier carrying the ACK/NACK channel resource is a secondary carrier ofthe highest priority among the first secondary carriers,

the determining unit 202 is further configured to:

determine priorities of secondary carriers among the first secondarycarriers according to the load of the ACK/NACK corresponding to thefirst uplink subframe on each secondary carrier where the first uplinksubframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier;

or, determine priorities for secondary carriers configured for the UE,where the determining specifically includes: for each time, determiningpriorities for all secondary carriers where a subframe corresponding tothe time is an uplink subframe; and

determine priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink frame.

The determining, by the determining unit 202, a secondary carriercarrying the ACK/NACK channel resource, includes:

if the network-side device schedules only one secondary carrier and doesnot schedule a primary carrier for the UE, and the secondary carrier isa second secondary carrier, determining, by the determining unit 202,the second secondary carrier as the secondary carrier carrying theACK/NACK channel resource.

The identifier of the control channel element CCE occupied by the PDCCHcorresponds to the ACK/NACK channel resource;

the determining, by the determining unit 202 according to the PDCCHinformation, an ACK/NACK channel resource corresponding to the PDSCH,includes:

determining, the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

In brief, the user equipment UE provided by this embodiment mayspecifically include:

a receiving unit, configured to receive physical downlink controlchannel PDCCH information transmitted by a network-side device to the UEin a downlink subframe;

a determining unit, configured to determine, according to schedulinginformation carried in the PDCCH information, a physical downlink sharedchannel PDSCH scheduled by the PDCCH information; determine, accordingto the PDCCH information, an acknowledgement ACK or negativeacknowledgement NACK channel resource corresponding to the PDSCH;determine, according to a timing relationship between the PDSCH and theACK/NACK corresponding to the PDSCH, a first uplink subframe used forfeeding back the ACK/NACK, where a subframe of the same time as thefirst uplink subframe is a downlink subframe on a primary carrier; anddetermine a secondary carrier carrying the ACK/NACK channel resource;and

a transmitting unit, configured to feed back, on the ACK/NACK channelresource determined by the determining unit, the ACK/NACK correspondingto the PDSCH, where the ACK/NACK channel resource is located in a firstuplink subframe of the determined secondary carrier.

The receiving unit is further configured to receive radio resourcecontrol RRC dedicated signaling transmitted by the network-side device;

the determining unit is further configured to obtain, according to theRRC dedicated signaling received by the receiving unit, an ACK/NACKresource set that is reserved by the network-side device for the UE in asubframe used for ACK/NACK feedback, where at least one ACK/NACK channelresource included in the ACK/NACK resource set is located on one ormultiple secondary carriers, and each ACK/NACK channel resource in theACK/NACK resource set is carried on a unique secondary carrier; and

the determining, by the determining unit according to the PDCCHinformation, the ACK/NACK channel resource corresponding to the PDSCH,includes:

obtaining, by the determining unit, the transmit power control TPC ordownlink assignment index DAI that is included in the PDCCH informationtransmitted by the network-side device and is used as an ACK/NACKchannel resource indicator ARI, and determining, in the ACK/NACKresource set according to the ARI, the ACK/NACK channel resource usedfor the UE to feed back the ACK/NACK, where the carrier carrying theACK/NACK channel resource is a carrier used for the UE to feed back theACK/NACK.

Correspondingly, the obtaining, by the determining unit, the TPC or DAIthat is used as the ACK/NACK channel resource indicator ARI, includes:

selecting one of the secondary carriers where the first uplink subframecorresponds to an uplink subframe, as a third secondary carrier;

using a TPC command word in the PDCCH information corresponding to thePDSCH carried on the third carrier as a TPC command word; and

using a TPC command word in the PDCCH information corresponding to otherPDSCHs as an ARI, where the other PDSCHs are carried on one or multiplesecondary carriers among other secondary carriers than the thirdsecondary carrier, and the ARI values are the same when the other PDSCHsare carried on multiple secondary carriers.

A subframe of the same time as the first uplink subframe is an uplinksubframe on the first secondary carrier.

If there is one first secondary carrier, the determining, by thedetermining unit, the secondary carrier carrying the ACK/NACK channelresource, includes:

determining the secondary carrier carrying the ACK/NACK channel resourceas the first secondary carrier;

and/or,

if there are two or more first secondary carriers, the determining asecondary carrier carrying the ACK/NACK channel resource includes:determining the secondary carrier carrying the ACK/NACK channel resourceas one first secondary carrier among the first secondary carriers,

where the one secondary carrier among the first secondary carriers isone of the following secondary carriers:

a secondary carrier of the highest priority, a secondary carrier of thelightest load, a secondary carrier of the lowest frequency, a secondarycarrier of the minimum index value, and a secondary carrier configuredby the network-side device for the UE through signaling.

Correspondingly, if there are two or more first secondary carriers, andthe secondary carrier carrying the ACK/NACK channel resource is asecondary carrier of the highest priority among the first secondarycarriers,

the determining unit is further configured to:

determine priorities of secondary carriers among the first secondarycarriers according to the load of the ACK/NACK corresponding to thefirst uplink subframe on each secondary carrier where the first uplinksubframe is an uplink subframe, or the frequency of each secondarycarrier, or the index configuration of each secondary carrier;

or, determine priorities for secondary carriers configured for the UE,where the determining specifically includes: for each time, determiningpriorities for all secondary carriers where a subframe corresponding tothe time is an uplink subframe; and

determining priorities of secondary carriers among the first secondarycarriers, where the determining specifically includes: obtainingpriorities of all secondary carriers where a subframe corresponding tothe time of the first uplink subframe is an uplink subframe.

The determining, by the determining unit, a secondary carrier carryingthe ACK/NACK channel resource, includes:

if the network-side device schedules only one secondary carrier and doesnot schedule a primary carrier for the UE, and the secondary carrier isa second secondary carrier, determining, by the determining unit, thesecond secondary carrier as the secondary carrier carrying the ACK/NACKchannel resource.

Correspondingly, the identifier of the control channel element CCEoccupied by the PDCCH corresponds to the ACK/NACK channel resource;

the determining, by the determining unit according to the PDCCHinformation, the ACK/NACK channel resource corresponding to the PDSCH,includes:

determining the ACK/NACK channel resource by using the identifier of aCCE among the CCEs occupied by the PDCCH.

The UE provided by this embodiment receives PDCCH informationtransmitted by a network-side device to the UE in a downlink subframe;determines, according to scheduling information carried in the PDCCHinformation, a PDSCH scheduled by the PDCCH information; determines,according to the indication of the PDCCH information, an ACK/NACKchannel resource corresponding to the PDSCH; determines, according to atiming relationship between the PDSCH and the ACK/NACK corresponding tothe PDSCH, a first uplink subframe used for feeding back the ACK/NACK,where a subframe of the same time as the first uplink subframe is adownlink subframe on a primary carrier; and determines a secondarycarrier carrying the ACK/NACK channel resource; and feeds back, on thedetermined ACK/NACK channel resource, the ACK/NACK corresponding to thePDSCH, where the ACK/NACK channel resource is located in a first uplinksubframe of the determined secondary carrier, so that the ACK/NACK canalso be fed back when carriers of different uplink and downlink subframeconfigurations are aggregated.

Embodiment 6

As shown in FIG. 12, this embodiment provides a network-side device,including:

a configuring unit 301, configured to configure at least two carriersfor a UE, where the carriers include one primary carrier and at leastone secondary carrier;

a transmitting unit 302, configured to transmit PDCCH information to theUE in a downlink subframe, where the PDCCH information indicatesscheduling information of a PDSCH carried in a downlink subframe; and

a determining unit 303, configured to determine at least two differentACK/NACK channel resources according to at least two timingrelationships between the PDSCH indicated by the PDCCH informationtransmitted by the transmitting unit 302 and the ACK/NACK correspondingto the PDSCH,

and determine a first channel resource from the at least two differentACK/NACK channel resources and use the first channel resource for the UEto feed back the ACK/NACK; where

the transmitting unit 302 is further configured to notify the UE of thefirst channel resource determined by the determining unit 303 throughsignaling;

a receiving unit 304, configured to receive the ACK/NACK fed back by theUE on the first channel resource determined by the determining unit 303.

The at least two timing relationships at least include timingrelationships that correspond to different carriers and/or correspond todifferent uplink subframes on a same carrier.

The at least two different ACK/NACK channel resources include: ACK/NACKchannel resources carried in uplink subframes of different carriers atthe same time, and/or, ACK/NACK channel resources in different uplinksubframes. Specifically, the ACK/NACK channel resources in differentuplink subframes may be different uplink subframes on different carriersor different uplink subframes on a same carrier.

The determining, by the determining unit 303, a first channel resourcefrom the at least two different ACK/NACK channel resources, includes:

selecting, according to loads of at least two different ACK/NACK channelresources, an ACK/NACK channel resource that has a lightest load, as afirst channel resource;

or, selecting, according to delays of at least two different ACK/NACKchannel resources, an ACK/NACK channel resource that has a shortestdelay, as a first channel resource;

or, determining, according to loads and delays of at least two differentACK/NACK channel resources, a first channel resource from the at leasttwo different ACK/NACK channel resources.

The notifying, by the transmitting unit 302, the UE of the first channelresource through signaling, includes one of the following:

notifying the UE of information about the first channel resource throughan added bit of the PDCCH information, a TPC, or a DAI;

determining, according to a mapping relationship between a scramblingcode and the ACK/NACK channel resource, a first scrambling codecorresponding to the first channel resource, and notifying the UE of thefirst scrambling code through PDCCH information; and

determining, according to a mapping relationship between a PDCCHtime-frequency resource position and the ACK/NACK channel resource, afirst PDCCH time-frequency resource position corresponding to the firstchannel resource, and notifying the UE of the first PDCCH time-frequencyresource position through PDCCH information.

The network-side device provided by this embodiment configures at leasttwo carriers for the UE, where the carriers includes one primary carrierand at least one secondary carrier; transmits PDCCH information to theUE in a downlink subframe, where the PDCCH information indicatesscheduling information of a PDSCH carried by a downlink subframe;determines at least two different ACK/NACK channel resources accordingto at least two timing relationships between the PDSCH and the ACK/NACKcorresponding to the PDSCH; determines a first channel resource from theat least two different ACK/NACK channel resources and uses the firstchannel resource for the UE to feed back the ACK/NACK; notifies the UEof the first channel resource through signaling; and receives theACK/NACK fed back by the UE on the first channel resource. Therefore,the ACK/NACK can also be fed back when carriers of different uplink anddownlink subframe configurations are aggregated. In addition, the loadsof ACKs/NACKs on carriers may be balanced, and the ACK/NACK feedbackdelay may be reduced.

The embodiment of the present invention further provides anothernetwork-side device. The implementation solution of the network-sidedevice is similar to the solution shown in FIG. 16, where thenetwork-side device may be a device in a TDD system, an FDD system, or asystem where TDD and FDD carriers are aggregated.

Specifically, as shown in FIG. 18, the network-side device may include:

A transmitting unit 181 is configured to notify a UE of carriersconfigured by a processing unit 182; transmit PDCCH information to theUE in a first subframe, where the PDCCH information indicates schedulinginformation of a PDSCH carried in a second downlink subframe; andindicate, to the UE, related information corresponding to a third uplinksubframe and a first carrier that are determined by the processing unitand a first channel resource.

The relationship between the first downlink subframe and the seconddownlink subframe, and the PDCCH information are specifically describedin Embodiment 2, and are not further described here.

The network-side device may also include a processing unit 182, which isconfigured to configure at least two carriers for the UE, where thecarriers include one primary carrier and at least one secondary carrier;select one of at least two timing relationships between the subframecarrying the PDSCH and a subframe carrying an ACK/NACK corresponding tothe PDSCH, as a first timing relationship, where on a first carriercorresponding to the first timing relationship, a subframe of the sametime as the second downlink subframe is a downlink subframe; determine athird uplink subframe corresponding to the first timing relationship andused for the UE to transmit the ACK/NACK corresponding to the PDSCH;determine the first carrier used for the UE to transmit the ACK/NACKcorresponding to the PDSCH; and in the determined third uplink subframeof the first carrier, determine a first channel resource used for the UEto feed back the ACK/NACK corresponding to the PDSCH.

The primary carrier and secondary carrier are specifically described inEmbodiment 2, and are not further described here.

The network-side device may include a receiving unit 183, which isconfigured to receive the ACK/NACK fed back by the UE on the firstchannel resource in the third subframe of the first carrier.

The processing unit may specifically include: a configuring unit, atiming relationship and subframe determining unit, a carrier determiningunit, and a channel resource determining unit.

The configuring unit is configured to configure at least two carriersfor the UE, where the carriers include one primary carrier and at leastone secondary carrier, and output configured carrier information to thetransmitting unit.

The timing relationship and subframe determining unit is configured toselect one of at least two timing relationships between the subframecarrying the PDSCH and a subframe carrying an ACK/NACK corresponding tothe PDSCH, as a first timing relationship, where the first timingrelationship meets a first condition, and the first condition is that ona first carrier corresponding to the first timing relationship, asubframe of the same time as the second downlink subframe is a downlinksubframe; and determine a third uplink subframe corresponding to thefirst timing relationship and used for the UE to transmit the ACK/NACKcorresponding to the PDSCH.

The carrier determining unit is configured to determine a first carrierused for the UE to transmit the ACK/NACK corresponding to the PDSCH.

The channel resource determining unit is configured to: in the thirduplink subframe determined by the timing relationship and subframedetermining unit, and on the first carrier determined by the carrierdetermining unit, determine a first channel resource used for the UE tofeed back the ACK/NACK corresponding to the PDSCH.

The timing relationship and subframe determining unit may bespecifically configured to: if the timing relationships correspond todifferent carriers, select one of at least two timing relationshipsbetween the subframe carrying the PDSCH and a subframe carrying anACK/NACK corresponding to the PDSCH, as a first timing relationship,where the first timing relationship meets the condition that on a firstcarrier corresponding to the first timing relationship, a subframe ofthe same time as the second downlink subframe is a downlink subframe andmeets one of the following conditions: a timing relationshipcorresponding to a carrier that has the lightest ACK/NACK channel loadamong different carriers; a timing relationship corresponding to acarrier that has the shortest ACK/NACK feedback delay among differentcarriers; and a timing relationship corresponding to a carrier wheretransmit power needed by the UE is the lowest among different carriers;and/or, if the timing relationships correspond to a same carrier, selectone of at least two timing relationships between the subframe carryingthe PDSCH and a subframe carrying an ACK/NACK corresponding to thePDSCH, as a first timing relationship, where the first timingrelationship meets the condition that on a first carrier correspondingto the first timing relationship, a subframe of the same time as thesecond downlink subframe is a downlink subframe and meets one of thefollowing conditions: a timing relationship corresponding to an uplinksubframe that has the lightest load in the same carrier; and a timingrelationship corresponding to an uplink subframe that has the shortestACK/NACK feedback delay in the same carrier; and determine a thirduplink subframe corresponding to the first timing relationship and usedfor the UE to transmit the ACK/NACK corresponding to the PDSCH.

Correspondingly, the carrier determining unit may be configured todetermine, according to the first timing relationship determined by thetiming relationship and subframe determining unit, a first carrier usedfor the UE to transmit the ACK/NACK corresponding to the PDSCH.

Or, the carrier determining unit is configured to determine a firstcarrier used for the UE to transmit the ACK/NACK corresponding to thePDSCH. And specifically, the carrier determining unit may specificallyselect, if different timing relationships correspond to differentcarriers, a carrier that corresponds to a timing relationship meetingthe first condition and meets one of the following conditions, as thefirst carrier: a carrier that has the lightest load is selected as thefirst carrier according to loads of ACK/NACK channels on differentcarriers; or a carrier that has the shortest feedback delay is selectedas the first carrier according to the ACK/NACK feedback delays on thecarriers; or a carrier where transmit power needed by the UE is thelowest among different carriers is selected as the first carrier.

Corresponding, the timing relationship and subframe determining unit maybe specifically configured to: if different timing relationshipscorrespond to different carriers, determine a corresponding first timingrelationship according to the first carrier determined by the carrierdetermining unit, and determine, according to the first timingrelationship and the subframe carrying the PDSCH, a third uplinksubframe used for the UE to transmit the ACK/NACK corresponding to thePDSCH.

The indicating, by the transmitting unit, the related informationcorresponding to the third uplink subframe and first carrier determinedby the processing unit to the UE, may be specifically: indicating theselected first timing relationship as the related information to the UE;or if the timing relationships correspond to different carriers, theindicating may be specifically: indicating the information about thefirst carrier as the related information to the UE.

The effect of the solution of this embodiment is similar to the effectof the method embodiment corresponding to FIG. 16, and is not furtherdescribed here.

Embodiment 7

As shown in FIG. 13, this embodiment provides a user equipment UE, wherethe UE includes:

a receiving unit 401, configured to receive PDCCH informationtransmitted by a network-side device to the UE in a downlink subframe,where the PDCCH information indicates scheduling information of a PDSCHcarried in a downlink subframe, where the receiving unit 401 is furtherconfigured to receive information about a first channel resource ofwhich the network-side device notifies through signaling and which isused for the UE to feed back an ACK/NACK, where the first channelresource is determined by the network-side device from at least twodifferent ACK/NACK channel resources that are determined by thenetwork-side device according to at least two timing relationshipsbetween the PDSCH and the ACK/NACK corresponding to the PDSCH; and

a transmitting unit 402, configured to feed back, on the first channelresource notified by the receiving unit 401, the ACK/NACK correspondingto the PDSCH to the network-side device.

The at least two timing relationships include at least timingrelationships that correspond to different carriers and/or correspond todifferent uplink subframes on a same carrier.

The at least two different ACK/NACK channel resources include: ACK/NACKchannel resources carried in uplink subframes of different carriers atthe same time, and/or, ACK/NACK channel resources in different uplinksubframes. Specifically, the ACK/NACK channel resources in differentuplink subframes may be different uplink subframes on different carriersor different uplink subframes on a same carrier.

The receiving, by the receiving unit 401 in the UE, information about afirst channel resource which is notified by the network-side devicethrough signaling and is used for the UE to feed back an ACK/NACK,includes one of the following:

receiving, by the UE, a first channel resource that is used for the UEto feed back the ACK/NACK and of which the network-side device notifiesthrough an added bit of the PDCCH information, a TPC, a DAI, a firstscrambling code corresponding to the first channel resource, or a firstPDCCH time-frequency resource position corresponding to the firstchannel resource.

The user equipment provided by this embodiment receives PDCCHinformation transmitted by the network-side device to the UE in adownlink subframe, where the PDCCH information indicates schedulinginformation of a PDSCH carried in a downlink subframe; receivesinformation about a first channel resource of which the network-sidedevice notifies through signaling and which is used for the UE to feedback an ACK/NACK, where the first channel resource is determined by thenetwork-side device from at least two different ACK/NACK channelresources that are determined by the network-side device according to atleast two timing relationships between the PDSCH and the ACK/NACKcorresponding to the PDSCH; and feeds back, on the first channelresource, the ACK/NACK corresponding to the PDSCH to the network-sidedevice, so that the ACK/NACK can also be fed back when carriers ofdifferent uplink and downlink subframe configurations are aggregated. Inaddition, the loads of ACKs/NACKs on carriers may be balanced, and theACK/NACK feedback delay may be reduced.

This embodiment further provides another user equipment, where theimplementation solution of the user equipment is similar to the solutionshown in FIG. 17. As shown in FIG. 19, the user equipment includes:

a receiving unit 191, a processing unit 192, and a transmitting unit193, where:

the receiving unit 191 is configured to receive information about twocarriers allocated by a network-side device for the user equipment UE,where the carriers include one primary carrier and at least onesecondary carrier; receive PDCCH information transmitted by thenetwork-side device to the UE in a first downlink subframe, where thePDCCH information indicates scheduling information of a PDSCH carried ina second downlink subframe; receive indication information transmittedby the network-side device, where a first timing relationshipcorresponding to the indication information meets a first condition: ina first carrier corresponding to the timing relationship, a subframe ofthe same time as the second downlink subframe is a downlink subframe;and receive information about a first channel resource allocated by thenetwork-side device for the UE and used for feeding back an ACK/NACKcorresponding to the PDSCH;

the processing unit 192 is configured to determine, according to theindication information received by the receiving unit, a third uplinksubframe and a first carrier that are determined by the network-sidedevice for the UE and used for ACK/NACK feedback; and determine,according to the information about the first channel resource receivedby the receiving unit, to transmit the ACK/NACK corresponding to thePDSCH on the first channel resource in the third uplink subframe of thefirst carrier; and

the transmitting unit 193 is configured to transmit the ACK/NACKcorresponding to the PDSCH on the first channel resource in the thirduplink subframe of the first carrier.

If the indication information received by the receiving unit 191 is afirst timing relationship selected by the network-side device,correspondingly the processing unit 192 is configured to determine,according to the first timing relationship and the second downlinksubframe carrying the PDSCH, a third uplink subframe used for the UE totransmit the ACK/NACK corresponding to the PDSCH, and determine,according to the mapping relationships between timing relationships andcarriers, the first carrier corresponding to the first timingrelationship; and determine, according to the information about thefirst channel resource received by the receiving unit, to transmit theACK/NACK corresponding to the PDSCH on the first channel resource in thethird uplink subframe of the first carrier.

If the indication information received by the receiving unit 191 isinformation about the first carrier, correspondingly the processing unit192 is configured to determine, according to mapping relationshipsbetween carriers and timing relationships, a first timing relationshipcorresponding to the first carrier, and determine, according to thefirst timing relationship and the second downlink subframe carrying thePDSCH, the corresponding third uplink subframe; and determine, accordingto the information about the first channel resource received by thereceiving unit, to transmit the ACK/NACK corresponding to the PDSCH onthe first channel resource in the third uplink subframe of the firstcarrier.

The effect of the solution of this embodiment is similar to the effectof the method embodiment corresponding to FIG. 17, and is not furtherdescribed here.

Embodiment 8

As shown in FIG. 14, this embodiment provides a network-side device,where the network-side device includes:

a configuring unit 501, configured to configure at least two carriersfor a UE, where subframe n of at least two carriers among the configuredcarriers is an uplink subframe and needs to feed back an ACK/NACK;

a dividing unit 502, configured to divide downlink subframescorresponding to the ACK/NACK that subframe n needs to feed back, intoat least two groups, where the number of downlink subframes in eachgroup does not exceed 2^(N)−1, where N indicates the number of bits of aDAI, where downlink subframes in at least one group belong to differentcarriers;

a setting unit 503, configured to set the DAI value in the PDCCHinformation corresponding to each downlink subframe in each groupobtained by division by the dividing unit 502 to 1 to 2N−1 in turn; and

a transmitting unit 504, configured to transmit the PDCCH informationcorresponding to the downlink subframes in each group, which is set bythe setting unit 503, to the UE.

The dividing unit 502 is specifically configured to:

group downlink subframes whose transmission time is within the first2^(N)−1 subframes on the first carrier among the downlink subframescorresponding to the ACK/NACK, into a first group, where the 2^(N)−1downlink subframes are called a first group of subframes; and

group other downlink subframes than the first group of subframes on thefirst carrier among the downlink subframes corresponding to theACK/NACK, and downlink subframes on the second carrier among thedownlink subframes corresponding to the ACK/NACK, into a second group,where the number of downlink subframes in the second group also does notexceed 2^(N)−1.

The case of two carriers is described above; for three or more carriers,and/or three or more groups, the processing principle is similar, andtherefore is not further described here.

The setting unit 503 is specifically configured to:

in each of the groups, set the DAI values from 1 to 2^(N)−1 in turnaccording to the transmission time sequence of the PDCCH information,where the DAI values are set again according to the carrier sequence forat least two downlink subframes of the same transmission time. Ofcourse, the setting of the DAI value may also use other manners, forexample, use the setting sequence learnt by both the network-side deviceand the UE.

The network-side device provided by this embodiment avoids the ACK/NACKfeedback information error by changing the DAI counting manner to avoidoverlapping of the ACK/NACK feedback information.

Embodiment 9

As shown in FIG. 15, this embodiment provides a user equipment UE,including:

a receiving unit 601, configured to receive at least two carriersconfigured by a network-side device, where subframe n of at least twocarriers among the configured carriers is an uplink subframe and needsto feed back an ACK/NACK;

a dividing unit 602, configured to divide the downlink subframes thatare received by the receiving unit 601 and correspond to the ACK/NACKthat subframe n needs to feed back, into at least two groups, where thenumber of downlink subframes in each group does not exceed 2^(N)−1,where N indicates the number of bits of a DAI, where downlink subframesin at least one group belong to different carriers; where

the receiving unit 601 is further configured to receive PDCCHinformation transmitted by the network-side device in each downlinksubframe in each group;

a generating unit 603, configured to: for each group that is obtained bydivision by the dividing unit 602, generate an N-bit ACK/NACK accordingto the DAI value in each piece of PDCCH information in the group and theACK/NACK corresponding to the PDSCH indicated by the PDCCH information;and

a transmitting unit 604, configured to transmit the ACK/NACK that isgenerated by the generating unit 603 and corresponds to each group tothe network-side device.

The user equipment provided by this embodiment avoids the ACK/NACKfeedback information error by changing the DAI counting mode to avoidoverlapping of the ACK/NACK feedback information.

All or a part of the contents disclosed in the technical solutionsaccording to the embodiments may be implemented by software programming.The programs may be stored in a computer readable storage medium, suchas a hard disk, a CD-ROM, or a magnetic disk.

The foregoing descriptions are merely exemplary embodiments of thepresent invention, but are not intended to limit the present invention.Any modification, equivalent replacement, or improvement derived withinthe spirit and principle of the present invention shall fall within theprotection scope of the present invention.

What is claimed is:
 1. A method for transmitting acknowledgement ornegative acknowledgement (ACK/NACK) indication information, comprising:configuring, by a network-side device, at least two carriers for a userequipment (UE), wherein the at least two carriers comprise a primarycarrier and a secondary carrier; transmitting, by the network-sidedevice, physical downlink control channel (PDCCH) information to the UEin a first downlink subframe, wherein the PDCCH information indicatesscheduling information of a physical downlink shared channel (PDSCH),and the PDSCH is carried in a second downlink subframe, whereinsubframes on the primary carrier and the secondary carrier at a timingof the second downlink subframe are downlink subframes; selecting, bythe network-side device, from a group consisting of at least two timingrelationships, timing relationship; determining an uplink subframecorresponding to the selected timing relationship, wherein the uplinksubframe is usable for the UE to transmit the ACK/NACK corresponding tothe PDSCH; and determining a carrier corresponding to the selectedtiming relationship usable for the UE to transmit the ACK/NACKcorresponding to the PDSCH; indicating, by the network-side device,information relating to the determined third uplink subframe and thedetermined carrier to the UE; determining, by the network-side device, achannel resource usable for the UE to feed back the ACK/NACKcorresponding to the PDSCH in the determined uplink subframe of thedetermined carrier, and indicating the channel resource to the UE; andreceiving, by the network-side device, the ACK/NACK fed back by the UEon the first channel resource in the determined uplink subframe; whereineach of the at least two timing relationships indicates a timing forsending an ACK/NACK in an uplink subframe relative to reception of adownlink subframe carrying the PDSCH; and wherein the group consistingof at least two timing relationships comprises: a first timingrelationship corresponding to the primary carrier and a second timingrelationship corresponding to the secondary carrier.
 2. The methodaccording to claim 1, wherein the selected timing relationship furthermeets at least one of the following conditions: the selected timingrelationship corresponds to a carrier that has a lightest ACK/NACKchannel load among carriers of the at least two carriers having adownlink subframe at the timing of the second downlink subframe; theselected timing relationship corresponds to a carrier that has ashortest ACK/NACK feedback delay among carriers of the at least twocarriers having a downlink subframe at the timing of the second downlinksubframe; and the selected timing relationship corresponds to a carriertransmit power needed by the UE is the lowest among carriers of the atleast two carriers having a downlink subframe at the timing of thesecond downlink subframe.
 3. The method according to claim 1, whereinthe determined carrier is determined according to mapping relationshipsbetween the at least two timing relationships and the at least twocarriers.
 4. The method according to claim 1, wherein the informationindicated to the UE comprises the selected timing relationship.
 5. Anetwork-side device, comprising: a transmitter, a receiver, and aprocessor, wherein the transmitter is configured to: notify a userequipment (UE) of carriers configured by the processor; and transmitphysical downlink control channel (PDCCH) information to the UE in afirst subframe, wherein the PDCCH information is used to indicatescheduling information of a physical downlink shared channel (PDSCH),and the PDSCH is carried in a second downlink subframe; wherein theprocessor is configured to: configure at least two carriers for the UE,wherein the at least two carriers comprise a primary carrier and asecondary carrier, wherein subframes on the primary carrier and thesecondary carrier at a timing of the second downlink subframe aredownlink subframes; select, from a group consisting of at least twotiming relationships a timing relationship; determine an uplink subframecorresponding to the selected timing relationship wherein the determineduplink subframe is usable for the UE to transmit the ACK/NACKcorresponding to the PDSCH; determine a carrier corresponding to theselected timing relationship usable for a UE to transmit the ACK/NACKcorresponding to the PDSCH; and determine a channel resource usable forthe UE to feed back the ACK/NACK corresponding to the PDSCH in theuplink subframe of the determined carrier; wherein the transmitter isfurther configured to indicate information relating to the determineduplink subframe, the determined carrier and the determined channelresource to the UE; wherein the receiver is configured to receive theACK/NACK fed back by the UE on the channel resource in the thirdsubframe of the determined carrier; wherein each of the at least twotiming relationships indicates a timing for sending an ACK/NACK in anuplink subframe relative to reception of a downlink subframe carryingthe PDSCH; and wherein the group consisting of at least two timingrelationships comprises: a first timing relationship corresponding tothe primary carrier and a second timing relationship corresponding tothe secondary carrier.
 6. The network-side device according to claim 5,wherein the selected timing relationship further meets at least one ofthe following conditions: the selected timing relationship correspondsto a carrier that has a lightest ACK/NACK channel load among carriers ofthe at least two carriers having a downlink subframe at the timing ofthe second downlink subframe; the selected timing relationshipcorresponds to a carrier that has a shortest ACK/NACK feedback delayamong carriers of the at least two carriers having a downlink subframeat the timing of the second downlink subframe; and the selected timingrelationship corresponds to a carrier for which transmit power needed bythe UE is the lowest among carriers of the at least two carriers havinga downlink subframe at the timing of the second downlink subframe. 7.The network-side device according to claim 5, wherein the informationindicated by the transmitter to the UE includes information about theselected timing relationship.
 8. A user equipment (UE), comprising; areceiver, a processor, and a transmitter, wherein the receiver isconfigured to: receive information about two carriers allocated by anetwork-side device for the UE, wherein the carriers comprise a primarycarrier and a secondary carrier; receive physical downlink controlchannel (PDCCH) information transmitted by the network-side device tothe UE in a first downlink subframe, wherein the PDCCH informationindicates scheduling information of a physical downlink shared channel(PDSCH), and the PDSCH is carried in a second downlink subframe, whereinsubframes on the primary carrier and the secondary carrier at a timingof the second downlink subframe are downlink subframes; receiveindication information transmitted by the network-side device, whereinthe indication information corresponds to a timing relationship, whereinthe timing relationship is one out of a group consisting of at least twotiming relationships, wherein each of the at least two timingrelationships indicates a timing for sending an ACK/NACK in an uplinksubframe relative to reception of a downlink subframe carrying thePDSCH, and wherein the group consisting of at least two timingrelationships comprises: a first timing relationship corresponding tothe primary carrier and a second timing relationship corresponding tothe secondary carrier; and receive information about a channel resourceallocated by the network-side device for the UE and usable for feedingback an acknowledgement or negative acknowledgement (ACK/NACK)corresponding to the PDSCH; wherein the processor is configured to:determine, according to the indication information, an uplink subframeand a carrier usable for ACK/NACK feedback; and determine, according tothe information about the channel resource, to transmit the ACK/NACKcorresponding to the PDSCH on the channel resource in the uplinksubframe of the determined carrier; and wherein the transmitter isconfigured to transmit the ACK/NACK corresponding to the PDSCH on thechannel resource in the uplink subframe of the determined carrier. 9.The user equipment according to claim 8, wherein the processor isfurther configured to, if the timing relationship is selected by thenetwork-side device and included in the indication information obtainedby the receiver, determine the uplink subframe usable for the UE totransmit the ACK/NACK corresponding to the PDSCH based on the selectedtiming relationship and the second downlink subframe carrying the PDSCH;and determine, according to mapping relationships between timingrelationships carriers, the determined carrier corresponding to theselected timing relationship.
 10. The user equipment according to claim8, wherein the processor is further configured to, if the indicationinformation received by the receiver comprises information about thedetermined carrier, determine, according to mapping relationshipsbetween carriers and timing relationships, the timing relationshipcorresponding to the determined carrier; determine, according to thetiming relationship and the second downlink subframe carrying the PDSCH,the corresponding third uplink subframe; and determine, according to theinformation about the channel resource received by the receiver, totransmit the ACK/NACK corresponding to the PDSCH on the channel resourcein the uplink subframe of the determined carrier.